3:4.8=5:x
3x=5*4.8
x=8
x:8/15=12
x=8/15*12
x=32/5
4:x=5/6
x=4*6/5
x=24/5
x:27/5=10/9
x=10/9*27/5
x=6
x:3.5=4:5
5x=3.5*4
x=14/5