4.8比5分之4 1比2.5 3分之2比9分之4 化简比.求比值

4.8:5分之4
=4.8:0.8
=4.8÷0.8:0.8÷0.8
=6:1
1:2.5
=1x2:2.5x2
=2:5
3分之2：9分之4
=3分之2x2分之9:9分之4x2分之9
=3:2