4 + 2(1 + x) = 12
6(5 - x) = 6
3(x + 1) - 2x = 0
2(3x - 1) + 2(4x + 5) = 8
2(x + 7) + x = 20
2(x - 1) + 3x = 3
x + 4(2x + 3) = 15
2(2x + 3) - 2 = 5
12 = 6(9 - x)
4(x + 2) - 2x = 0
x = 7
x = 3
x = 1/3
x = -4
x = -3
x = 0
x = 4
x = 1
x = 1/4
x = 2
