№ 3
1) 4 - (5x + 8) = -4x + 10
4 - 5x - 8 = -4x + 10
-5x + 4x = 10 - 4 + 8
-x = 14
x = -14
2) 13 - (9x - 6) = 8x + 19
13 - 9x + 6 = 8x + 19
-9x - 8x = 19 - 13 - 6
-x = 0
3) 29 - (15x + 8) = -14x + 13
29 - 15x - 8 = -14x + 13
-15x + 14x = 13 - 29 + 8
-x = -8
x = 8