x-5/8x=15
(3/8)x=15
x=15*(8/3)
x=40
1/5x+3/10x=120
2/10x+3/10x=120
5/10x=120
x=120*2
x=240
20%x=30
x=30/20%
x=150
(1-45%)x=1.95
55%x=1.95
x=1.95/0.55
x=39/11