(a×2.5)分之a(1+0.25)×10=5

问题描述:

(a×2.5)分之a(1+0.25)×10=5

假设是a+2.5,不然没法算
a(1+0.25)×10/(a+2.5)=5
a(1+0.25)×10=5(a+2.5)
2ax1.25=a+2.5
2.5a=a+2.5
1.5a=2.5
a=3分之5