Помогите решить пж.........................​

Ответ:

1) (х-2)(х-11)-2х(4-3х)=х²-11х-2х+22-8х+6х²=7х²-21х+22

2) (а+6)(а-3)+(а-4)(а+5)=а²-3а+6а-18+а²+5а-4а-20=2а²+4а-38

3) (у-8)(2у-1)-(3у+1)(5у-2)=2у²-у-16у+8-(15у²-6у+5у-2)=у²-17у+8-(15у²-у-2)=2у²-17у+8-15у²+у=-13у²-16у+10

4) (х+2)²-(х-3)(х+3)=х²+4х+4-(х²-9)=х²+4х+4-х²+9=4х+13

5) (7а-5b)(7a+5b)-(4a+7b)²=49a²-25b²-(16a²+56ab+49b²)=49a²-25b²-16a²-56ab-49b²=33a²-74b²-56ab

6) (y-2)(y+3) -(y-1)²+(5-y)(y+5)=y²+3y-2y-6-(y²-2y+1)+(5-y)(5+y)=y²+y-6-y²+2y-1+25-y²=3y+18-y²