3х - 5 + 2х = -4 + 7х + 3

5х - 5 = -1 + 7х

5х - 7х = -1 + 5

-2х = 4

х = -2

___________________

-7х + 3х + 2х = -4 + 3 + 5

-2х = 4

х = -2

Получается: -2 = -2