(x+1)*百分之30+(100-x)*百分之25=2/5x

问题描述:

(x+1)*百分之30+(100-x)*百分之25=2/5x

(x+1)*百分之30+(100-x)*百分之25=2/5x
方程两边同乘以100得:
30(x+1)+25(100-x)=40x
再在方程的两边同除以5得:
6(x+1)+5(100-x)=8x
6x+6+500-5x=8x
6x-5x-8x=-6-500
-7x=-605
x=605/7