If you multiply a negative by a negative, you get a positive answer. Since all the terms in the equations are negative (or zero), if you multiply by -1, all the negatives will become positives (and the zero remains zero). I hope that helps
If I had the equation 3x = 9, I would be able to multiply everything by 2 to get 6x = 18. If I had the equation -4x = -8, I could add 4x to both sides to get 0 = -8 + 4x and then I could add 8 to both sides to get 8 = 4x. A shortcut if you have an equation like -4x = -8, is to multiply both numbers by -1. So -4x times -1 is 4x and -8 times -1 is 8 (as a negative times a negative = positive). The step where I multiplied by -1, all the terms were negative, so I times everything by -1 to make them positive. (I also cheekily changed their order).
this really helped me thank you!! i have my maths mock next week and I was stressing about this part of it
3:22 why do you multiple 3 by minus 1??
ikr i'm confused at that point of the video too
If you multiply a negative by a negative, you get a positive answer. Since all the terms in the equations are negative (or zero), if you multiply by -1, all the negatives will become positives (and the zero remains zero). I hope that helps
corbettmaths ah seen, thank you so much
Thank you so much bro 🙏🙏
Sir how do you get that mode on your calculator where there is a blinking cursor?
thanks a very clear video and a great help!!!
Confusing... you didn't explain why you multiplied it by -1
If I had the equation 3x = 9, I would be able to multiply everything by 2 to get 6x = 18. If I had the equation -4x = -8, I could add 4x to both sides to get 0 = -8 + 4x and then I could add 8 to both sides to get 8 = 4x. A shortcut if you have an equation like -4x = -8, is to multiply both numbers by -1. So -4x times -1 is 4x and -8 times -1 is 8 (as a negative times a negative = positive). The step where I multiplied by -1, all the terms were negative, so I times everything by -1 to make them positive. (I also cheekily changed their order).
At around 6:14, shouldn’t you have subtracted 30, giving you x^2-11x-30?
No, I actually kept the 30 on the right hand side and brought the other terms to that side