Question

Помогите сделать 821))))

Answer 1

$1) 4(7-5x)-(12-20x)=28-20x-12+20x=16 \ 2)2(3x-y)-(5x-2y)=6x-2y-5x+2y=x \ 3)6(x+2y)-3(2x+y)=6x+12y-6x-3y=9y \ 4)5(4x+y)-2(x-y)=20x+5y-2x+2y=18x+7y$

Answer 2

1 - 16
2- x
3 - 9y
4- 18x + 7y