X+4x=20
5x=20
x=4
6m-3m=27
3m=27
m=9
2y+y=105
3y=105
y=35
2y+4y=15
6y=15
y=5/3
9x-4x=6.5
5x=6.5
x=1.3
8n-n=14
7n=14
n=2