7 - (1 - 3x) = 12
(2x - 1) - (x - 7) = 2
(3x - 2) - (2x + 3) = 0
5x/2 = 10
2x/5 + 3 = 7
x / 5 - 1 = 2
4
- 4
10
2
5
15
