X - 1/4X =4/5X +1/4X -30
问题描述:
X - 1/4X =4/5X +1/4X -30
答
X - 1/4X =4/5X +1/4X -30
X - 1/2X =4/5X -30
1/2X =4/5X -30
3/10X=30
X=100