8 X（x+1/5）= 3.2
x+0.2=0.4
x=0.2
x+7/2=1/5x+11.5
x-0.2x=11.5-3.5
0.8x=8
x=10
20%x=3/5 - x
x+0.2x=0.6
1.2x=0.6
x=5
3/5 X (x - 50%)=1/10
3/10x=1/10
x=1/3
1/2x - 41/10=150%x-8.3
1.5x-0.5x=8.3-4.1
x=4.2
1/4X(x - 0.75) = 13/16
x-0.75=13/16x4
x-3/4=13/4
x=13/4+3/4
x=4