Simplifying Expressions With Roots and Exponents

Поделиться
HTML-код
  • Опубликовано: 20 дек 2024

Комментарии •

  • @alonsorobots
    @alonsorobots 3 года назад +223

    Damn, I feel like following the Mathematics (All of it) playlist, this one took a jump in complexity!

    • @jerrytom8835
      @jerrytom8835 Год назад +19

      I started scratching my hair lol.

    • @hazarsoysal146
      @hazarsoysal146 Год назад +5

      @@jerrytom8835 same

    • @aLittlePal
      @aLittlePal Год назад +6

      he left out the in-between content regarding the concept and operation of exponents, so when he solves a mixed problem involved both exponents and roots, some of us will feel confused

    • @deesnuty
      @deesnuty 9 месяцев назад +2

      Compare this 5-10 minute lesson to 1 hour lesson in school

    • @TJStudies-xm5ty
      @TJStudies-xm5ty 6 месяцев назад +1

      @@aLittlePalCan you help me explain the 6:50 parts?

  • @commandosolo1266
    @commandosolo1266 Год назад +100

    Explanations of the answers:
    1. (2x^2 y^4 z^5) ^3 -- As you recall, when cubing elements with exponent we simply multiply. So 2 cubed is 8, x^2 cubed is x^6, y^4 cubed is y^12, and z^5 cubed is z^15.
    2. Remember that because the exponent is negative, we get rid of it by inverting the fraction. So now we have (x^2y over xy^2) squared. We multiply the exponents, yielding X^4 Y^2 over X^2 Y^4. That cancels to give us X^2 over Y^2.
    3. Let's substitute Y=3, chosen at random. X^ (6+1) over X^(6-1) gives us X^7 over X^5. Cancel out, and we're left with X^2.
    4. Good golly Dave, way to crank up the difficulty! This is just mean.
    Okay, remember that the "2" in the exponent is also a 2/1. So now we can multiply the exponents. X^1/3 by 2/1 gives X^2/3. The other term, X^2/3s multiplied by 2/1 gives us X^4/3s. So now we have X^2/3 times X^4/3 divided by X^3/2.
    Now we go ahead and multiply X^2/3 by X^4/3, which means we add the numerators, giving us X^6/3. (which is the same as X-squared, but in this case we'll convert it to X^4/2, a common denominator.) Now when we divide X^4/2 by X^3/2, we subtract the numerators, yielding X^1/2. Whew!
    (At least I think that's how it works. If I've come to the right answers by erroneous methods, by all means show us your method.)

    • @ta_ogboy9998
      @ta_ogboy9998 Год назад +12

      Good detailed explanations!
      Another way for option 4 would to do this (the way I did it):
      (x^1/3 * x^2/3)^2 = (x^1/3 * x^2/3) (x^1/3 * x^2/3)
      Since we are multiplying exponents, we add them. So in that case, it's just adding fractions:
      (x^1)(x^1)
      Anything to the power of 1 is itself:
      (x)(x)
      This is the same as x to the power of 2:
      x^2
      That's the same as x^2/1:
      x^2/1 divided by x^3/2
      When dividing exponents, you have to subtract. So we are substracting fractions, and to do this, we have to change the equation to where both have the same denominator (LCM):
      x^4/2 divided by x^3/2
      Subtract fractions:
      x^1/2
      Also note that your method is not bad, and actually I like yours better. I simply stated this as an alternative method to anybody who may come across your comment.

    • @randompersonsfather6077
      @randompersonsfather6077 Год назад +1

      how to know if we need to convert and how to convert on situations like this please explain and also the conversion of the 4th question x raised to 6/3

    • @slickyy21
      @slickyy21 Год назад +1

      Multiplying Two Different Fractions Means:
      Adding Those Fraction's Numerators , For Addition , we must first we assured that their denominators are common (or same) if they are not we'll have to find out Least common multiple (LCM) of denominators .
      After finding LCM we'll have to mutiply both denominators with that factor that will make the value of denominator equal to LCM
      From then on we can continue the addition of numerators, 'cause now the denominators are equal.
      But in this case their denominators are already common so we just have to add their numerators which gives us : x^6/3
      I hope that clear up your confusion!

    • @geneva4034
      @geneva4034 Год назад

      for the second one, how come we have to multiply the exponents? Is there a symbol or exponent? I thought we got rid of the -2 so we can invert the fraction. What is multiplying it now?

    • @geneva4034
      @geneva4034 Год назад

      Nevermind, just rewatched the video. You don't get rid of the -2. You actually just invert it's operation. Thanks for the help anyways

  • @axelmont
    @axelmont 4 месяца назад +25

    Ok, this video is pretty good, but the jump in difficulty is in big part because some rules of exponents and radicals are assumed in the resolution of the examples, but have not been thoroughly explained in previous videos in the series. I recommend Nerdstudy's playlist on Algebra I where he goes through each rule. That made this video a lot clearer to me.

    • @edfromchowderheads1312
      @edfromchowderheads1312 3 месяца назад +3

      I second that after watching a few of his videos, makes it a bit easier to understand

  • @basketguitar9768
    @basketguitar9768 10 месяцев назад +20

    On 3x^2√32y^2 - 4y √18x^4, they cut the 32 in half to take its root, and they leave the √2 since you cant do anything with it. They combine 3x • 4y because mutliplication is associative (doesnt matter what order you multiply), so it is valid, and left us with 12x^2y√2
    Same thing on the other side.
    It took me a few days to understand this, and I don't want other people to face the same issue so hopefully this helps.

  • @CartoonKidOLLY
    @CartoonKidOLLY 2 года назад +186

    I was doing fine up until this point...

    • @Anon-hj7il
      @Anon-hj7il 2 года назад +16

      same here I'm lost with this one

    • @Canis_Fatalis
      @Canis_Fatalis 2 года назад +30

      I'm also stuck. Weird to think this is 8th grade level mathematics and I'm STILL struggling with it at age 21. I only got half right on the comprehension check.

    • @Anon-hj7il
      @Anon-hj7il 2 года назад +18

      @@Canis_Fatalis Try to watch it again but each example analyze how he did it
      I've been able to solve it all after an hour 😅

    • @riteshkumar018
      @riteshkumar018 2 года назад +4

      😂

    • @errebusaether
      @errebusaether 2 года назад +4

      🤣 You’ll get used to it.

  • @JaylouRasonabe
    @JaylouRasonabe 9 месяцев назад +45

    This video took a curve with the my learning progress, but I will never leave this video until I fully grasp the concept.

    • @MoneyWrack
      @MoneyWrack 3 месяца назад +1

      Same here I am doing the same thing

  • @angelt1538
    @angelt1538 3 месяца назад +3

    This is way easier than I remember when I watched this months ago! Thank you for making this lessons free.

  • @Mythtongue
    @Mythtongue 11 месяцев назад +15

    The difficulty jump is wild. Yet, not unwanted. I know with time and repetition i'll be able to simplify with ease!

  • @brandonampang2199
    @brandonampang2199 10 месяцев назад +11

    This is the point in 7th grade where I realized math is getting harder

  • @alexandrugrancea2170
    @alexandrugrancea2170 Год назад +10

    Explanation of the third exercise:
    So we have x^(2y+1)/x^(2y-1)
    The first term can also be written as x^2y*x^1
    The second one as : x^2y*x-1
    So we have : x^(2y+1)-(2y-1) taking into consideration that when we have minus before a parathesis we multiply the terms by -1 therefore the +2y cancels with -2y and because -1 became +1 we remain with +1+1 => x^2
    The last one it s even essier if you dont do the mistake i did and start as you should by calculating the parathesis, by doing so you will have x^2/x^3/2 which equals x^1/2

    • @aaaawqer1233
      @aaaawqer1233 9 месяцев назад

      i had problem only with the third and this answer explanation to me everything, ty

  • @Student_ye
    @Student_ye Год назад +16

    This was a tuff vid, but just a few more replaying this video. I got it now thanks!!

  • @bashdota1553
    @bashdota1553 Год назад +21

    I'm 26years old, looking forward to completing the playlist to get prepared for engineering education that I'm willing to start soon. This playlist been perfect so far. I'd only wish if there were more comprehension questions in the video or linked to it. Thanks a lot prof!

    • @letzte_maahsname
      @letzte_maahsname Год назад +4

      28 y/o here, about to start undergraduate studies in pharmaceutical sciences. It's never too late to start! All the best for your engineering courses.

    • @Danny-df4po
      @Danny-df4po 11 месяцев назад +1

      I am 14

    • @nemesis6819
      @nemesis6819 11 месяцев назад

      ​@@letzte_maahsname how's it going

    • @nemesis6819
      @nemesis6819 11 месяцев назад

      ​@@Danny-df4pokeep up the good work 💪

    • @tmchannel8483
      @tmchannel8483 9 месяцев назад

      Literally me

  • @DaveyLers5150
    @DaveyLers5150 11 месяцев назад +34

    Damn, professor Dave aint fucking around this time....

    • @Arconic_Tower
      @Arconic_Tower 4 месяца назад

      😂😂😂

    • @sophiahank4407
      @sophiahank4407 2 месяца назад

      True

    • @sophiahank4407
      @sophiahank4407 2 месяца назад

      😂😂😂😂😂😂

    • @sophiahank4407
      @sophiahank4407 2 месяца назад

      I bet he’d be yapping for hours about this until he realized it was a fucking video

    • @hthree7857
      @hthree7857 10 дней назад

      Professor Dave done dancing around the pot, he now jumping in taking us with him

  • @goabeaches6036
    @goabeaches6036 4 года назад +9

    I saw Leonardo Da Vinci's biography and came to know how a person can be jack of all trades and here I came to learn some maths after getting inspired by Da Vinci!
    Professor Dave is making my life much easier. Thank u very much ❤️

  • @MarianaLafoskayl
    @MarianaLafoskayl 7 месяцев назад +3

    Bro it's so complex but u made it easy asf!! I really love your videos and still go on w learning mathematics with you!!

  • @user-fz5un7vp3e
    @user-fz5un7vp3e 2 года назад +5

    man, i really love your videos! i used to hate math but grew to love the subject because your videos made me realize that math isn't that bad at all. thanks a lot, professor dave!

  • @brae9land557
    @brae9land557 3 месяца назад +3

    Great teacher I decided to do the comprehension test at the end and did all of them in my head and did it correctly my first go 👍

  • @afrinshahnaz8031
    @afrinshahnaz8031 Год назад +5

    Explanation of 2nd and 4th one:
    2nd ques-
    (xy2/x2y)^-2
    = (x2y/xy2)^2 (becoz there is -2 whole power ,so to make it positive we have to reverse it , as x-1=1/x)
    =x4y2/x2y4 (now cut x2/x4 and y2/y4)
    =>x2/y2 final ans.
    4th ques:
    (X⅓ . X⅔)^2\X³/²
    =(X⅓×2 . X⅔×2)/X³/² (solve power individually )
    =(X⅔. X⁴/³)/X³/² (now add numerator powers 2/3+4/3)
    =X⁶/³ divided by X³/² ( now cut 6/3)
    =X2-³/² =X²/¹ --- ³/²
    =X4-3/2 => X1/2 (final ans)
    Thank you for listening my Explanation 💜

    • @itsdemonz9814
      @itsdemonz9814 Год назад

      Can you explain #3 for me. I feel like #2 was easier to understand for my brain lol

    • @oshuwareafegbai6114
      @oshuwareafegbai6114 2 месяца назад

      How did you get x4-3/2?

  • @FrancescoDiSiena
    @FrancescoDiSiena 5 месяцев назад +1

    in check comprehension, in the second in the first line i got x^2y^-2, but if you change the y^-2 in 1/y^2, and then you do x^2/1 times 1/y^2, the result is the same. in the last, i just wrote x^1/2 like square root of x, so is the same

  • @jadelerio2790
    @jadelerio2790 Год назад +3

    For practice question #4 is my method right? Pls correct me if not.
    x^6/3 divided by x^3/2 but we should make it have a common denominator first...
    so: 6/3 x 1/2 and 3/2 x 1/3 which will give us 6/6 - 3/6 or simply 1-1/2
    so: x^1/2 or square root is the answer.

  • @Twichery
    @Twichery Год назад +2

    Short answer for last question. it might be wrong
    top side we sum the powers in paranthesis 1/3+2/3=1
    x^1=x
    so we have x in paranthesis
    x^2 we have at top
    down side has 3/2 divider is 2 so we have to make the upside same like x^2=x^4/2
    now we drag the down side 3/2 to upside as negative
    4/2-3/2 = 1/2
    so we are left with x^1/2
    when i try to explain it takes some time but its short tbh

  • @athar_adv
    @athar_adv 2 года назад +3

    In 6:53, you can turn the root (9•2)x⁴ into 3x² because when you combine the two, you need to take the square root of them to get them outside the square root
    If that makes sense

  • @is_neme3169
    @is_neme3169 5 месяцев назад +1

    Okay I have a question
    At 6:37 time stamp he said we can combine” like terms” the expression is 3x₂ 4y √2 -> 12x₂ y√2 …now my problem how are the values 3 and 4 like terms? It could be rewritten as 3 apples squared x 4 oranges , could you now have 12 apples squared x an orange ? Like x and y are different aren’t they? Can you operate their quantities as like terms? (sorry for the inverted square sign :))

  • @Twichery
    @Twichery Год назад +3

    Sure, let's break it down.
    So, you have something that looks like this: ((x^(1 part) * x^(2 parts))^2)/x^(3 parts).
    Let's start with (x^(1 part) * x^(2 parts)). That means x has 1 part plus 2 parts, which equals 3 parts or just x.
    Now we square it (meaning we times it by itself) so now it looks like this: (x * x) or x^2.
    In the denominator, we have x^(3 parts). That's like x, but times itself again, so we get 1.5 parts (x^1.5).
    Finally, we subtract the bottom part from the top part. So, 2 parts (from x^2) - 1.5 parts (from x^1.5) equals 0.5 parts or x^0.5.
    So at the end, you get x^0.5. And that's the answer! You can also say "x to the power of half" or "square root of x".

  • @vitustillebeck4965
    @vitustillebeck4965 3 года назад +8

    This is extremely hard. especially because im 13 years old. but i went over this video with my dad and i then watched the upcoming videos and im starting to get the hang of it. it was tough but it payed of. best of luck.

    • @teos4664
      @teos4664 2 года назад +9

      because this is high school tier math :) you will get there one day bud. take it easy and good luck with your studies!

    • @vitustillebeck4965
      @vitustillebeck4965 2 года назад +4

      @@teos4664 Thank. It got way easier. Good luck to you too.

  • @laurentiamaria
    @laurentiamaria 5 дней назад

    I have to admit it gets harder in this video. I'll get back to this later so, bookmark 4:06.
    Edit: I'm so glad I finally comprehend the concept properly and completed this video. Thank you so much!

  • @ffnoobx3214
    @ffnoobx3214 5 месяцев назад +1

    At 6:35 why we only took 4y why not 4y^2 ??

    • @Arconic_Tower
      @Arconic_Tower 4 месяца назад +1

      because y² was under the √ root
      √y² = √y*y = y !

  • @fahadshaikh5686
    @fahadshaikh5686 Год назад +1

    Problem at mark of 4:07 the flipping over i don't get it

  • @1dunno_u
    @1dunno_u Год назад +2

    U teach better than my school teacher.

  • @Esselo
    @Esselo Год назад +2

    You know its getting serious when he starts sounding like a quarterback changing the play

  • @MarianaLafoskayl
    @MarianaLafoskayl 6 месяцев назад +1

    U are the beat professor Dave!

  • @datanerden1057
    @datanerden1057 6 месяцев назад +1

    One thing to notice if some people didn't get it: the whole expression in parenthesis changes sign if a minus is in front of it.

  • @jc_9359
    @jc_9359 4 года назад +2

    @ 4:33 Why do you flip the fraction to make the exponent positive?

  • @TheKids422
    @TheKids422 2 месяца назад +1

    Wow man, this is tricky and I need a lot of time.

  • @amosll151
    @amosll151 3 года назад +13

    Great explanations.. I am just really wishing you had a link to how you got the answers to the comprehension questions at the end of all of your videos..

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 года назад +3

      most of them show the work

    • @NickHope
      @NickHope 3 года назад +13

      @@ProfessorDaveExplains I'm up to lesson 35 and didn't see any workings for any of the comprehension questions yet.

    • @НиколайУльянкин-г6т
      @НиколайУльянкин-г6т 3 года назад +1

      @@ProfessorDaveExplains Hello, David. Thank you for the lesson.
      I would like to clarify one point:
      in the part (9x^5•y^5) / x^6, we divide x^5 by x^6 and get x^-1 and this is the same as 1\x. But then why do we still have 9 there, and not 10?
      After all, we have 9 + 1 remaining from the reduction operation, don't we?

    • @Doobaloo
      @Doobaloo Год назад +1

      @@НиколайУльянкин-г6т well no because that 1 is part of the exponent

    • @ange.000
      @ange.000 Год назад +2

      ​​​​@@НиколайУльянкин-г6т It's because 1 is multiplying, it is not adding. When it was x^-1 it was multiplying 9, so when it became 1/x, 1 was still multiplying, NOT adding, so 9 times 1 is still 9, not 10 :)

  • @brenazelda224
    @brenazelda224 2 года назад +3

    Hi I'm new and I'm learning I'm trying to catch up of my school gade ty Dave for all of ur mathematics videos ^v^

  • @Ricardoelpr356
    @Ricardoelpr356 3 месяца назад +1

    I had to see this video 3 times in a row to understand it

  • @end4567
    @end4567 2 года назад +4

    Mh, as others have said, this is becoming really difficult all of a sudden. I don't even think the exercises are that hard. I mean, I almost got them right, it's just that there's so many things I have to keep track of. I really don't think I'll ever be able to memorize those. Maybe I'll skip for now and hopefully come back and understand better once I'm further into the playlist. I'm in the last year of HS, all I want is to pass the final exams. Hopefully I can do it.

  • @volatilesteps
    @volatilesteps 5 месяцев назад

    6:19
    but how did it work if by the denominator just can not be 0?

  • @ingvark1968
    @ingvark1968 5 лет назад +2

    Hi again Dave, sorry about my previous comment. I strugled a little bit more and found what I had made wrong. Now I get the same result as you. So, it must be right to flipp the expressin inside the brackets. And thanks again for your exelent lessons. / Ingvar

  • @SCRKT007
    @SCRKT007 Год назад +2

    6:33 Really need a more in-depth explanation on this one because you went so fast, I just can't comprehend how a square root of (16•2)y² suddenly became a 4y square root 2, and somehow the y² became a single y?? Idk at all...

    • @itsdemonz9814
      @itsdemonz9814 Год назад +2

      If you watch the Playlist in order I think the video before this one explains how to simplify square roots and cubes roots.
      Basically the inverse operation of y^2 or y squared would be to get the squared root so instead of (16•2)y^2 you can do the square root of 16 and 2. This looks like /16 • /2... 4 is the square root of 16 so that's where the 4 comes from and /2 or square root of 2 comes from.
      You leave the square root of 2 looking as is because if you solved for that number you will get a long repeating number that'll make the while equation look ugly. You want your equation to be simple aka simplified so that's why you dont solve for it. Anyways, now your equation should look something like 4y•/2. The reason the 4 gets a y and not the 2 is because you solved for y by using the square root! Because you can't get a whole number by solving for the square root of 2 aka /2 you leave it there alone, no y because that was the whole point of doing the square root. Remember the inverse operation of a variable squared is to find the square root and vice versa. I hope this helped but if it didn't, I'd recommend going back a video in the Playlist in understanding those basics of simplifying square roots.

    • @MichaelLeightonsKarlyPilkboys
      @MichaelLeightonsKarlyPilkboys Год назад

      @@itsdemonz9814 You solved a huge headache for me!
      I couldn't figure out why the y^2 became a y and you reminded me that you are finding the square root of y^2 which is of course y.
      Thank you so much!

    • @itsdemonz9814
      @itsdemonz9814 Год назад +1

      @@MichaelLeightonsKarlyPilkboys no problem. These equations can get tricky. Glad I could help

    • @ceegae1670
      @ceegae1670 4 месяца назад

      ​@@itsdemonz9814 hello, may I ask why √(16.2).y^2 isn't √16y^2 . √2y^2 ? It conflicts with the distribution thing we learned earlier parts

  • @daifan4488
    @daifan4488 2 года назад

    Why no PEMDAS at 2:48? I still got the right result using PEMDAS, but what's the point of doing it the way it's done in the video?

    • @ta_ogboy9998
      @ta_ogboy9998 Год назад +2

      In one of his videos he explains how distributive property works. It won't matter if you distribute first and then do inside the parentheses, or do the partentheses and then distribute.
      For example:
      5(2+3)
      You can do PEMDAS:
      5(5)
      25
      Or you can distribute:
      10+15
      25
      Both ways are valid methods, it's simply up to one's preferences.

  • @Theblessedone11
    @Theblessedone11 4 месяца назад +2

    how is the answer for the fourth comprehensive question x^1/2 it should be x^-1
    or 1/x

    • @Arconic_Tower
      @Arconic_Tower 4 месяца назад

      ^ means to the power of and ----- is the fraction line
      1)
      (x^⅓ * x^⅔)²
      -------------
      x^3/2
      2) Distribute ² across parenthesis [ (xⁿ)ⁿⁿ = xⁿ*ⁿⁿ ]:
      (x^⅓)² * (x^⅔)²
      -----------------
      x^3/2
      x^⅔ * x^4/3
      -----------
      x^3/2
      3) Multiply the numbers in numerator [ xⁿ * xⁿⁿ = xⁿ+ⁿⁿ ]:
      x^6/3
      -----
      x^3/2

      -----
      x^3/2
      4) Simplify [ xⁿ / xⁿⁿ = xⁿ-ⁿⁿ ]:
      x^(2-3/2)=x^1/2
      Answer is x^1/2 !

  • @deesnuty
    @deesnuty 9 месяцев назад

    In the compression x ^ 1/2 can be simplified even further to square root of x which is which is just X is the simplest form

  • @tramarthomas6105
    @tramarthomas6105 3 года назад +1

    Edit: read my reply since that's confused
    Yeah, this hard to do, but it'll be easy to forget since a lot of this stuff I'd be doing without no explanation. Like the flipping the fraction to flip the negative exponent, then having to square both the top and bottom. I was hoping to do the general chemistry playlist just from the information in these videos but I can tell that won't be an option

    • @tramarthomas6105
      @tramarthomas6105 3 года назад

      For anyone else that's confused, there are a few videos and websites online that explains this very nicely. The best thing in my opinion is just to revisit fractions and exponents, since there's no harm in that. But if you don't want to, look up reciprocals. Also look the rules of exponents, a really good site for it is called mathematics monsters. Thinking about it now, I'm sure Dave covered all of this in his arithmetic playlist so check if he did first.

  • @weiwang2357
    @weiwang2357 4 месяца назад

    @2:04 commutative property, not associative.

  • @ian_7775
    @ian_7775 Год назад

    why does the negative sign distribute at 6:06 ?

  • @Mywmca
    @Mywmca Год назад +2

    I need to learn but with you I can’t

    • @MarianaLafoskayl
      @MarianaLafoskayl 7 месяцев назад

      So you mean that u can't learn it with that teacher?!

  • @ahmadalsalti8127
    @ahmadalsalti8127 2 года назад +1

    it took me 60 min to complete this video, but now I know Kong-fu :)

  • @anjalysatheesan7794
    @anjalysatheesan7794 3 года назад +2

    Can you please explain the second problem? I don't get it.

  • @sislol3685
    @sislol3685 4 года назад +2

    If you flip the fraction then the exponents change symbol like from negative to positive right?

  • @adenikebankole7859
    @adenikebankole7859 2 года назад +2

    Hello Prof! I'm afraid I didn't get the (second?) question (xy / x2y)-2 . The answer I keep getting is x2.
    I flipped it since it's an inverse squared operation. (x2y/xy)2
    I squared the nominator and denominator (x2y)2 / (xy)2 to get x4y2 / x2y2.
    Since Y2 is common, it's taken off to leave x2
    Please how did you arrive at x2/y2 ?

    • @adenikebankole7859
      @adenikebankole7859 2 года назад

      How did I miss the squared on letter y of the numerator of the question. Lol
      I got them all!

    • @nouhaila5506
      @nouhaila5506 2 года назад

      ((xy2)÷(x2y)) -2 = (y÷x) 2 ( we get rid of the x above and the y in the base then we can flip the nominator and the denominator to get (x÷y) 2 which gives us x2÷y2 as the final result

    • @halcyonXT
      @halcyonXT Год назад +1

      y^2 is not common, you square the y^2 to get y^4, after which you divide to get (x^2*y^-2). inverse square to get x^2*((1/y)^2) then replace the 1 with x^2 to get x^2 / y^2

  • @BoeingPrototype
    @BoeingPrototype 4 года назад +4

    Hi David . Thanks for the videos. Can I just ask, at 3:31 you multiply the numerators x^3 and x^2 and you write x^5 and not x^6.
    Why would this be?
    Thanks once again

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  4 года назад +15

      Well x^3 is x x x, and x^2 is x x, so that's five all together, or x^5. You only multiply the exponents when raising one to the other.

    • @BoeingPrototype
      @BoeingPrototype 4 года назад +3

      @@ProfessorDaveExplains Thanks :)

  • @swift1793
    @swift1793 2 года назад +3

    I GOT IT ALL RIGHT!

  • @someaussiekidd
    @someaussiekidd 5 лет назад

    At 6:38 why is the left over root 2 not root 2y? Isn't 16x2 in the brackets equal to 16y x 2y? So when you remove the 4y should there still be a y left

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 лет назад +4

      but the square root of y^2 is y, so you take y^2 completely out of the root

    • @someaussiekidd
      @someaussiekidd 5 лет назад +1

      @@ProfessorDaveExplains ohhhhhhhhhhhh of course. Thanks so much for replying by the way, you're amazing. I'm currently studying for the GAMSAT (MCAT for Australia and the UK) and your channel has helped me so much (ive been watching heaps of your chem videos too). I'm currently doing my masters in medical research, and so I have a pretty good grasp of science as a whole, but my mathematics is so lacking it's embarrassing. There's so many little rules like this that accumulate into a solid understanding of mathematics (regretting not trying harder in highschool every day) and unfortunately it doesn't seem like there are an shortcuts. Would you have any recommendations/sources, apart from going topic by topic, where someone a little further on in their careers can go and practice the basics? (Really fishing for shortcuts here -_-)

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 лет назад +6

      well i really tried my best to provide an ultra-comprehensive math course that covers all the basics in addition to the advanced topics, so i would just head into my mathematics playlist and everything you need should be in there! good luck :)

    • @someaussiekidd
      @someaussiekidd 5 лет назад +2

      @@ProfessorDaveExplains Thanks so much for your reply again. And I think this is the first maths one I've watched so I will definitely continue.
      I've been using tutorial videos to study for many years now and honestly I've only found your channel recently. At the moment I actually prefer your stuff over Khan academy or others because you start simple (for people like me) but still extend the concepts to their complexity which is where you actually start realistically applying them, and your comprehension section at the end is great. Also your intro jingle is dope.
      Thanks again dave, i honestly can't express how much people including myself appreciate the work people like you do. Science education is so important!

  • @madhurikumari8937
    @madhurikumari8937 Месяц назад

    Can anyone explain me the forth question at 07:35

    • @ulpinight5665
      @ulpinight5665 28 дней назад

      I can explain it to you, but not in the comments. I can't really write the full explanation here...

    • @popcorn_and_zero-coke_lady_fan
      @popcorn_and_zero-coke_lady_fan 8 дней назад

      You use power rule to the numerator so you multiply the numerator of the exponent since there's always an invisible 1 as denominator on whole number
      x^2/3•x^4/3
      Then multiply or just add the numerator based on product rule
      x^6/3
      Now you have
      x^6/3 over x^3/2
      ("over" means denominator since it would be confusing)
      Use LCM to the exponents
      x^12/6 over x^9/6
      Use quotient rule or just subtract the exponent
      x^3/6
      Simplify as
      x^1/2
      I recommend you to watch FreeCodeCamp algrebra video since it was explained there more clearly and use Dave's video as practice and refresher since this has questions.

  • @SSS23585
    @SSS23585 9 месяцев назад +1

    I want to be a quantum physicist, but I gotta master the basics, and this sure does the job. As my grandpa said, you can’t learn a language without knowing the alphabet.

  • @carlosott1866
    @carlosott1866 3 года назад +2

    I'm confused, in the last example you took the square root of 16y² and got 4y. Couldn't it be -4y as well since an even root has two possible answers? Same goes for the square root of 9x^4, in the same example, which became 3x²; couldn't it also be -3x²?

    • @0Coeus
      @0Coeus 3 года назад

      When taking the square root, we only consider the positive case, and when solving equations (like x^2=16) we consider both positive and negative. If you would like an explanation for why we do this, I made a comment about it in the previous video in the playlist :)

  • @adhil8918
    @adhil8918 4 года назад

    6:36 that's is y² how you put only y. The y is common for both 4 and √2.

    • @mindfake_5587
      @mindfake_5587 4 года назад +1

      the square root of y^2 is y. since y * y = y^2. So he basically took the two factors 16 and y^2 out of the square root which became 4y

    • @waaawooo
      @waaawooo 2 года назад

      y is also inside the square root

  • @5yazkhn
    @5yazkhn 4 года назад +2

    7:41 x square, please explain this.?
    3rd problem

    • @deltakid0
      @deltakid0 4 года назад +2

      You take the denominator multiplied by numerator so "x ^ - (2y-1)" then the sum of exponents will be "2y + 1 - 2y + 1" the 2y goes out and only "1 + 1" is left.

  • @felipejshon3663
    @felipejshon3663 Год назад +1

    In no.4, where did you get the 4/2?

  • @madanprajuli1630
    @madanprajuli1630 11 месяцев назад +1

    Hi Professor Dave Everything was going fine, but I am not able to undertand any single questions here, kindly make it easier

    • @basketguitar9768
      @basketguitar9768 10 месяцев назад +1

      It's difficult for you because you didn't watch his other videos or you don't know the basics. It makes sense, and I commented explaining how it works.

  • @thegoodlydragon7452
    @thegoodlydragon7452 4 года назад +2

    6:37 I'm a little confused by this part. I thought 3xsquared and 4y wouldn't be like terms since they're attached to different variables, like 9 apples and 4 oranges.

    • @johnn522
      @johnn522 4 года назад

      same here!

    • @ristaglista3378
      @ristaglista3378 4 года назад +6

      When you are doing multiplication (or addition), the order of operations doesn't matter. Whichever order you choose, you'll always get the same result. 2x3x4x5 is the same as 3x4x5x2 (both equal to 120). AxBxCxD is the same as BxCxDxA. And likewise 3X4Y is the same as 12XY, only the order changed.

    • @adhil8918
      @adhil8918 4 года назад

      @@ristaglista3378 where is another y there is y²

  • @salah1x
    @salah1x 3 года назад +5

    Now I remember why I hated math🥲.
    I was starting to love it until I saw this, Then I remembered when I used to flip things all over the place and memories the steps and forget on the exam
    Edit: after repeating I now understand but I'm sure I'll forget and do it in another way next time and mess everything up

    • @EKDupre
      @EKDupre 3 года назад +6

      Friend, your skills won't grow if you're preparing yourself to mess up. Stay diligent, yet easy on yourself. Mistakes are chances to learn, so appreciate them!

  • @GamerSaga
    @GamerSaga 6 лет назад +2

    hello, question for you while I am understanding for the most part how you solve for example the 64/x6 2/3 square. but i never really understood what it would be used for or the many variations for solving equations?

    • @m3nny125
      @m3nny125 2 года назад

      This can be used for bulky equations with tons of stuff on both sides to simplify it to something like x^4=81

  • @ericnlopezpagan2699
    @ericnlopezpagan2699 3 года назад +1

    @profesor dave explains could you help me out on question 3? I can either get (2y+1)/(2y-1) or 0 not x²

    • @krustew17
      @krustew17 2 года назад +3

      it's because you subtract them, (2y+1)-(2y-1) and then the - in the parrenthesies flip into + because - times - equals +, so it's 2y+1-2y+1, 2y cancels and you're left with 1+1 equals 2

    • @quite0079
      @quite0079 22 дня назад

      @@krustew17 i scrolled so far down searching for better explanation on 3rd problem thanks brother

  • @kellycanicus421
    @kellycanicus421 4 года назад +1

    Thanks for the lessons. I don't understand why at 3:36 x cube times x square is x to the 5th power not the 6th power. Please help.

    • @kellycanicus421
      @kellycanicus421 4 года назад

      ☺️ I um found your video explaining. Thanks for the great videos!😁👍

    • @zerosandones7547
      @zerosandones7547 4 года назад

      Yeah Idk why this happened too

  • @oliaquino4049
    @oliaquino4049 Год назад

    Hey how come in the previous example 5a[(2x+y)-(x+y)] you got 5a^x by elimination.. but in the comprehension exercise 2 x^(2y+1)/x^(2y-1) which is x[(2y+1)-(2y-1)] and you got X^2 . .. should the 2y and 1 have been eliminated resulting in x^0? I keep getting x^0. Not sure if this was answered i didnt check the comment thoroughly. Thanks

    • @oliaquino4049
      @oliaquino4049 Год назад

      I got it... when u distribute the negative sign it became 2y+1 . Making it x^2 .

  • @livewithashley
    @livewithashley 4 месяца назад

    where can i find worksheets with these topics to practice? please if anyone has a site or any kind of worksheet source

  • @Wildasf1
    @Wildasf1 6 месяцев назад +1

    Where can i find exercise to practice?

  • @NdukaUche
    @NdukaUche Год назад

    Question 4 in the comprehension was tricky but atleast i now know how to solve it

  • @rationalism_communism
    @rationalism_communism 7 месяцев назад +2

    sorry but why isnt the second answer x2 over y-2

  • @89dz1
    @89dz1 Год назад +1

    I understood until 6:37😭😭

  • @agentfifteen
    @agentfifteen Год назад

    I finally get it thanks!

  • @Jeff_Segal
    @Jeff_Segal 4 года назад +2

    Great series! I’ve always said « all squared » rather than « quantity squared » , but I am Australian...

    • @zunaslogic4128
      @zunaslogic4128 3 года назад +2

      We say "whole squared" here in South Asia.

  • @gwenturo9550
    @gwenturo9550 Год назад +1

    Im having trouble figuring out how CQ#3 is x²..... I just got x.
    Where did i go wrong?

    • @oliaquino4049
      @oliaquino4049 Год назад

      same here. It contradicts the previous example he had. Which is subtracting the elements.

  • @ThingsOut
    @ThingsOut Год назад +1

    At this point I’m confused.. 5:55

  • @teos4664
    @teos4664 2 года назад +2

    can someone explain why x^(2y+1) / x^(2y-1)= x^2 ?

    • @Anon-hj7il
      @Anon-hj7il 2 года назад

      because since they both have the base as X so we will minus the exponents like this
      [ ( 2y+1) - (2y-1) ] = 2y + 1 - 2y + 1 = 2 then it would be x^2

  • @johnn522
    @johnn522 4 года назад +1

    could anyone explain how did we get X1/2 in the comprehension?

    • @ristaglista3378
      @ristaglista3378 4 года назад +13

      Just take notes of all the techniques he uses and use them yourself one step at a time. I'll try to explain with words, but it's gonna look a bit messy. Anyway, this is how I did it and got X to the power of 1/2:
      1) distribute the exponent in the upper fraction (leave bottom fraction as it is for the time being)
      2) multiply the X's (just add their exponents together)
      3) then you get ( *X* to the power of 6/3) / ( *X* to the power of 3/2)
      4) since 6/3 = 2, you end up with *X* squared / ( *X* to the power of 3/2)
      5) subtract the exponents from each other
      You end up with *X* to the power of 1/2, which is the same as the root of *X* .

    • @johnn522
      @johnn522 4 года назад +1

      @@ristaglista3378 Thanks alot! but my problem is with distributing the first step , i can't really find an example in this video or the exponents one about squaring variables with fractioned exponents.
      (x⅓)² =? and (x⅔)²= ? do we deal with fractioned exponents as normal fractions ? because when we multiply fractions we multiply the denominator and the numerator and it doesn't seem that you've done that!
      the square of a number 2² is 2x2 but what about the square in this case ? ⅓ x ⅓ and ⅔ x ⅔ ?
      ruclips.net/video/lWAsS82pyYA/видео.html Got it!
      thanks again.

    • @crazywrathmusikband2228
      @crazywrathmusikband2228 4 года назад

      @@ristaglista3378 , thanks a lot dude:^)(◕ᴗ◕✿)(◕ᴗ◕✿)w(°o°)w♪┌|∵|┘♪

    • @adhil8918
      @adhil8918 4 года назад

      @@ristaglista3378 thanks to remember the addition of exponents

    • @zunaslogic4128
      @zunaslogic4128 3 года назад

      (X⅓ • X⅔)²/X³/²
      = (X²/³ • X⁴/³)/X³/²
      = (³√(X² • X⁴)/X³/²
      = (³√X^6)/X³/²
      = (³√X³ • X³)/X³/²
      [the cubes cancel out the cube root]
      = X • X/(√X³)
      = X²/(√X² • X)
      [the square cancels out the square root]
      = X²/X • √X
      [one X from X² cancels out with the X in the denominator]
      = X/√X
      = X/X½
      [there are two halves in one whole]
      = X½ • X½ / X½
      [one term from the numerator cancels out with the denominator]
      = X½

  • @Aleggbriel1
    @Aleggbriel1 Год назад

    In the last example problem, what happened to the ys?

  • @breakingbad2456
    @breakingbad2456 3 года назад

    Thanks Dave

  • @ingvark1968
    @ingvark1968 5 лет назад +5

    Hi Dave, your lessons are realy interesting. But, now I have got a problem. In the comprehension at the end of the lesson I solved the problem your way and came to the same result as you. However I was a little questining about the flippening of the number inside the brackets and change of the exponent. So, I put in real number in the expression and solved the problem the simpiest way. But that did not give me the same answer as I got when I used your "flipping". I put in X = 3 and Y = 9 and got 15.52 / 9 or 1.732 with mine way. Your way I got 9/81 or 0.111. Quite a differens. Are you sure your way of doing it is correct?

    • @ta_ogboy9998
      @ta_ogboy9998 Год назад

      I just put it in the calculator, and both ways should be 1/9 or 0.1 repeated. So don't worry, his way is correct.

    • @ange.000
      @ange.000 Год назад +1

      Algebra is about using variables (letters), so when we change those variables to random numbers with no justification at all, it won't always be right, that's why it didn't gave you the correct answer. I recommend you only using letters in these scenarios :)

  • @moe583
    @moe583 Год назад +1

    I feel like a couple of rules could've been explained before this video like inverting the fraction when you're applying a negative exponent to it

  • @thida6549
    @thida6549 Год назад +1

    The answer of question 4 is 1/x? right?

  • @geohayek9943
    @geohayek9943 4 года назад +1

    can someone explain to me the ;ast problem i couldnt do it

    • @AspenMyra33
      @AspenMyra33 3 года назад

      I'd like to see the answer worked out too, please!

    • @zunaslogic4128
      @zunaslogic4128 3 года назад +1

      (X⅓ • X⅔)²/X³/²
      = (X²/³ • X⁴/³)/X³/²
      = (³√(X² • X⁴)/X³/²
      = (³√X^6)/X³/²
      = (³√X³ • X³)/X³/²
      [the cubes cancel out the cube root]
      = X • X/(√X³)
      = X²/(√X² • X)
      [the square cancels out the square root]
      = X²/X • √X
      [one X from X² cancels out with the X in the denominator]
      = X/√X
      = X/X½
      [there are two halves in one whole]
      = X½ • X½ / X½
      [one term from the numerator cancels out with the denominator]
      = X½

  • @ignacioleikis1784
    @ignacioleikis1784 4 года назад

    Possible spoiler!
    Can we simplify question 4 even further by writing x^1/2=root of x?
    Edit: Also, when simplifying algebraic expressions, do we strictly abide by the same rules of PEMDAS?
    when evaluating algebraic equalities/inequalities, do we perform PEMDAS backwards?

    • @0Coeus
      @0Coeus 3 года назад +2

      It is a matter of choice. They are both equivalent statements, and the word "simplify" is a bit of a misnomer in this situation. Neither is form is simpler than the other, they are merely usefull for different situations.

    • @ericnlopezpagan2699
      @ericnlopezpagan2699 3 года назад

      Yes

  • @bruhhh69
    @bruhhh69 Год назад +2

    I couldn't keep up with this one.

  • @onlygoodpartloop
    @onlygoodpartloop 10 месяцев назад

    (x^1/3 . x^2/3 ) 2 / x^3/2 = {x ^(1/3+2/3) }^2 / x^3/2 , {x^(3/3) }^2/x^3/2 , (x) ^2 / x^3/2 , x^(2 - 3/2) , x^ (4 -3/2) = x^1/2

  • @jostmathe
    @jostmathe 3 года назад

    wow thank you a lot, how can i give my thanks to appreciate your guidance

  • @andrewkorsten2423
    @andrewkorsten2423 Год назад +1

    the videos were very clear before this on, but this one took a huge elevation in compleixty

  • @aparnamukerji1485
    @aparnamukerji1485 2 года назад +1

    can some one please explain the third practice question?

  • @Jovan-Marquis
    @Jovan-Marquis Год назад

    yeah this one is like a lighting jump compared to the others lol

  • @TherealYUVRAJ
    @TherealYUVRAJ 3 месяца назад +2

    ohhh so this is where it all went downhill for me.

  • @NeuroSwathi
    @NeuroSwathi Год назад +1

    Brain-storming! btw loved it, got 3 right, the last one had a silly mistake.

  • @chad8519
    @chad8519 Год назад +1

    Oof, this was a meat grinder of a lesson

  • @TJStudies-xm5ty
    @TJStudies-xm5ty 6 месяцев назад

    Someone explain 6:50 to me please.

    • @James-hs1eq
      @James-hs1eq 6 месяцев назад

      Which part specifically don't you understand from that process? In √(9 • 2) x⁴, the reason why Prof. Dave broke up 18 like that is so that we can get the perfect square 9 and get the root of it which is 3, but we can also do the same thing to x⁴, its root being x². By doing this we leave only 2 inside the square root and we can combine like terms, leaving us with 12x²y √2.

    • @Clipsandedits1224
      @Clipsandedits1224 5 месяцев назад +1

      Sorry for being late
      1st. Let's focus on the Root (32y²). We can convert that to Root (16 • 2 • y²), that would equal to 4x y • Root(2), and now we just multiply 3x² by 4y Root(2). which is just 12x²y Root(2). Now we do 4y • Root(18x⁴) which is converted to Root(9 •2 •x⁴) which is 3x² • Root(2) now We multiply 4y by 3x² • Root(2) which is 12x²y • Root(2) now we subtract 12x²y • Root(2) - 12x²y • Root(2) which is equal to 0

    • @ffnoobx3214
      @ffnoobx3214 5 месяцев назад

      ​@@James-hs1eqbro why he wrote y from y2 at 3rd step and x2 but it was x4??

  • @Jesuisunknown
    @Jesuisunknown 2 года назад +1

    How did (3√x^6)^2 become (x6)^1/3?

    • @ta_ogboy9998
      @ta_ogboy9998 Год назад

      Cube root (^3√) is the same as saying ^1/3
      ^2√ = ^1/2
      ^4√ = ^1/4
      ^3√2^2 = 2^2/3
      ^5√3^6 = 3^6/5
      The exponent outside is the denominator, and the exponent inside is the numerator.
      Do you see the pattern?

  • @neck-o
    @neck-o 2 года назад +1

    Can someone kindly explain to me why I lack the braincells

  • @chourouk-gr9qg
    @chourouk-gr9qg 5 месяцев назад

    ty

  • @invictussol2116
    @invictussol2116 13 дней назад

    I guess we shouldn't have skipped the Laws of Exponents.