Question

Упростите выражения.
1.(а-4)(а+4)-(а+2)2
2.(у-3)2-(у-5)(у+5)
3.2х(х+7)- 2(х-3)(х+3)
4.(х-5)х - (х+9)(х-9)
5 (у+10)(у-2)-(у+3

Answer 1

1)(a-4)(a+4)-(a+2)2=a²-16-2a-4=a²-2a-20

2)(y-3)2-(y-5)(y+5)=2y-6-y²+25=y²+2y+19

3)2x(x+7)-2(x-3)(x+3)=2x²-14x-2x²+18=-14x+18

-14x=-18

x=-18/-14, x=9/7

4)(x-5)x-(x-9)(x+9)=x²-5x-x²+81=-5x+81

-5x=81

x=81/5

5)(y+10)(y-2)-(y+3)=y²-20+10y-2y=y²+8y-20

(x-10)(x-2)

x=10, x=2