2+7x-4-3x
4x-8x
-5-2x+3-8x-2
1+3x+2x-7
4x-8x+6x
5x+2-x+10
X-18+2x-3
3x-21
-7+12-2
4x-2
5x-6
-7-6x+12
4x+12
10x-4
