9/13/8+1/8*7/13
=9/13*1/8+1/8*7/13
=1/8*（9/13+7/13）
=1/8*16/13
=2/13
5/8：x=3:16
3x=5/8x16
3x=10
x=10/3
x+1/4x-4=32
x+x/4=32+4
5x/4=36
x=36x4/5
x=144/5
1/4=0.75/x
x=4x0.75
x=3
1.4x- 0.6=7.8
1.4x=0.6+7.8
1.4x=8.4
x=8.4/1.4
x=6