2x+6=5x
5x-2x=6
3x=6
x=2
6x-28=2x
6x-2x=28
4x=28
x=7
8(x-3.6)=0.8x
8x-0.8x=28.8
7.2x=28.8
x=4
15x-110+7x=110
15x+7x=110+110
22x=220
x=10