8x-3x=105
5x=105
x=21
x-0.36x=16
0.64x=16
x=25
13.2x+9x=33.3
22.2x=33.3
x=1.5
2x+1.5x=17.5
3.5x=17.5
x=5
2x-x=41.6
x=41.6