(500*95%)/(500+x)=75%

问题描述:

(500*95%)/(500+x)=75%

(500*0.95)/(500+x)=0.75
475/(500+x)=0.75
475=(500+x)*0.75
475=500*0.75+0.75x
475=375+0.75x
0.75x=100
x=100/0.75
x=400/3