Question

Срочно помогите 7 класс

Answer 1

1) (3a + 5) + (2a - 1) = 3a + 5 + 2a - 1 = 5a + 4

2) (5x - 2y) + (y - x) = 5x - 2y + y - x = 4x - y

3) (7a - 2b + 1) + ( 7a - 2b + 1) = 7a - 2b + 1 +  7a - 2b + 1 = 14a - 4b + 2

4) (9x - y + 7) + (y - 7 - x) = 9x - y + 7 + y - 7 - x = 8x

5) (a + b + c) + (- a - b - c) = a + b + c - a - b - c = 0

6) (a - 2b + 3c) + (- 3a + 2b - c) =  a - 2b + 3c - 3a + 2b - c = - 2a + 2c