(30-x)(解50-x)=50*30*75%怎么解

问题描述:

(30-x)(解50-x)=50*30*75%怎么解
RT

(30-x)(50-x)=50*30*75%
1500-80x+x^2=1125
x^2-80x+375=0
(x-5)(x-75)=0
x=5 or x=75