4/5*甲=3/4*乙甲：乙=3/4:4/5=15:16
4x/5=3y/416x=15yx:y=15:16
x×4÷5=y×3÷4x/y=15/16
(3/4)x=(4/5)yx/y=(3/4)/(4/5) =15/16
