[(1-20%)y-75%x]/(75%x)＝25%
问题描述：
[(1-20%)y-75%x]/(75%x)＝25%
答
[(1-20%)y-75%x]/(75%x)＝25%
(1-20%)y/(75%x）-75%x/(75%x)＝25%
80%y/(75&x)-1=25%
80%y/(75&x)=25%+1
80y/75x=125
16y/15x=125
16y=1875x
答
[(1-20%)y-75%x]/(75%x)＝25%
{(1-0.2)y-0.75x}/0.75x=0.25
(0.8y-0.75x)/0.75x=0.25
0.8y-0.75x=0.1875x
0.8y=0.1875x+0.75x
0.8y=0.9375x
答
4/5y-3/4x=3/4xX1/4 即y=75/64x