4x/7+8=60%x
3x/5-4x/7=8
(21/35-20/35)x=8
x/35=8
x=280
x/20+1/2=1/2x/8
x/20+1/2=x/16
(5/80-4/80)x=1/2
1/80x=1/2
x=40