2x - x = x
15x + 8x = 23x
3 · 7 + 6 = 20 + 7
2x + 8x = 10x
2a + 3a = 5a
2(4x + 5) = 2(4x - 2) + 14
30 + 8y = -7y
14/2 + 5 · 5 = 29 + 3
5 + 6x = -4 - 3x
-7 + 3x = x - 3
4x + 1 = 5x - 8
2x+7=3
x + 2x - 1 = 3x - 1
5 + 2 = 7
6 = -2x
