Ответ:

1) x = 14

2) x = -0.8

3) x = 11.5

Пошаговое объяснение:

1) 3x - 10x + 6x = 9 + 5

-x = 14

x = 14

2) -5(3x - 4) - (x + 2) = 5(6 - x)

-15x + 20 - x - 2 = 30 - x

-15x - x + x = 30 - 20 + 2

-15x = 12

x = -0.8

3) 2x - 3(2x + 5) = (4 - 3x)2

2x - 6x - 15 = 8 - 6x

2x - 6x + 6x = 8 + 15

2x = 23

x = 11.5