1) х = - 3/5 ; 2) х = 5/12 ; 3) х = 11 .

Объяснение:

1) 5x - 7 = 4

5х = 4 + ( - 7 )

5х = - 3

х = - 3/5

2) - 2x = 5 - 14x

- 2х + 14х = 5

12х = 5

х = 5/12

3) 2х - 7 = 4 + х

2х - х = 4 + 7

х = 11