Question

815помогите пожалуйста срочно)

Answer 1

1) $=7-5x-3+5x=4$
2) $=6x-2y-5x+2y=x$
3) $=2x+4y-2x-y=3y$
4) $=20x+5y-2x+2y=18x+7y$

Answer 2

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