x:2/3=3/5:1/4解:1/4X=2/3*3/5 1/4X=2/5 X=8/5(或1.6)
x:2/3=3/5:1/43x/2=12/5x=12/5*2/3x=8/5
1/4÷2/3=3/83/8÷3/5=8/5