5X+10(40-X)=3605X+10(40-X)=360怎么做?急,晚上就要用?
问题描述:
5X+10(40-X)=360
5X+10(40-X)=360怎么做?急,晚上就要用?
答
5X+10(40-X)=360
5X+400-10X=360
400-5X=360
5X=40
X=8