Can you Solve Stanford University Admission Interview Question?✍️🖋️📘💙

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  • Опубликовано: 13 дек 2024

Комментарии • 11

  • @nisse_1235
    @nisse_1235 День назад +2

    Solve for b to get b = (44-a^2) / (1+2a).
    The denominator is positive for all non-negative a.
    Since b is non-negative, it means that the numerator must be non-negative.
    Hence, we only need to test the values a=0,1,2,3,4,5, and 6 and see which ones give integer values for b.

  • @fuerdichundmich
    @fuerdichundmich День назад +1

    a^2 has to be < 44, therefore a can only be 1,2,3,4,5 or 6.
    For a=1: 44-1= 3*b no solution in Z.
    For a=2: 44-2^2=5*b b=8
    For a=3: 44-3^2=7*b. b=5
    For a=4: 44-4^2=9*b no solution in Z
    For a=5: 44-5^2=11*b. no solution in Z
    For a=6: 44-6^2=13*b. no solution in Z.
    There are two pairs that solve the equation: a=2; b=8
    and a=3; b=5

    • @jaredprince4772
      @jaredprince4772 9 часов назад

      If a=0, b=44.

    • @fuerdichundmich
      @fuerdichundmich 6 часов назад

      @ the solution has to be in Z+(as mentioned in the very beginning), therefore Zero is no solution.

    • @jaredprince4772
      @jaredprince4772 32 минуты назад

      @@fuerdichundmich You're right. I was thinking that it was positive, but it is neutral.

  • @abufikri4241
    @abufikri4241 14 часов назад

    You made it the hard way
    a and b are positive integer
    a² + 2ab + b = 44
    (a+b)² - a² - 2ab - b² + a² + 2ab + b = 44
    (a+b)² + b - b² = 44
    (a +b)² > 44
    If (a +b)² = 49, b - b² = -4, roots are not integers
    If (a +b)² = 64, b - b² = -20, b ≠ -4, b = 5, hence a = 3
    If (a +b)² = 81, b - b² = -37, roots are not integers
    If (a +b)² = 100, b - b² = -56, b ≠ -7, b = 8, hence a = 2

  • @kateknowles8055
    @kateknowles8055 18 часов назад

    I thought of b=8 a=2 2ab= 32 a^2= 4 . This adds 4+32+8= 44.
    But I started from: suppose (a+b)(a+b)= 10x10=100
    You can start from somewhere of your choosing and come up with answers of all sorts. Did not see any restrictions on validity of answers.

  • @deathcall6663
    @deathcall6663 День назад

    Yo, why did we asume that 2a+1

    • @dlevi67
      @dlevi67 День назад +2

      If a, b є Z+, then (once eliminating the 2a on left and right) you are left with 1 < 4b-1, which considering that the minimum value of b in Z+ is 1, is true for all b.

    • @MataniMath
      @MataniMath День назад +1

      b = (44-a²)/(2a+1) and (2a+1)>0.
      If (2a+1) > (2a+4b-1), then (in this case) a > 6 which causes b will negative. But the condition is that a and b are positive. So (2a+1) must be less than (2a+4b-1)