11a+8a+9a+11a
20ax-16ax
15x+20x+x
3/8am - 5/4 am
15ab-9ab
-15ab+15ab
-101mn+118mn
4ax - 1/8 ax
-14xy+32xy
1/2 a - 3/4 a
31/8 ax
- 1/4 a
6ab
- 7/8 am
17mn
0
36x
4ax
18xy
39a
