Решение:
- 6x = 28 - x
6x + x = 28
7x = 28
x = 4 - 11x + 35 = 6x
11x - 6x = -35
5x = -35
x = -7 - 9x + 7 = 3x + 37
9x - 3x = 37 - 7
6x = 30
x = 5 - 9x - 7 = 5x + 29
9x - 5x = 29 + 7
4x = 36
x = 9 - 7x - 15 = 21 - 5x
7x + 5x = 21 + 15
12x = 36
x = 3 - 5(x - 6) = x + 2
5x - 30 = x + 2
5x - x = 2 + 30
4x = 32
x = 8 - 2 - 3(2 + 3x) = 14
2 - 6 - 9x = 14
-4 - 9x = 14
-9x = 14 + 4
-9x = 18
x = -2 - -11x = 7 - 3(5x - 3)
-11x = 7 - 15x + 9
-11x = 16 - 15x
-11x + 15x = 16
4x = 16
x = 4 - 0,4x + 4,5 = 2,1 - 0,8x
0,4x + 0,8x = 2,1 - 4,5
1,2x = -2,4
x = -2
Ответ: 1) x = 4; 2) x = -7; 3) x = 5; 4) x = 9; 5) x = 3; 6) x = 8; 7) x = -2; 8) x = 4; 9) x = -2.