3X+(100-X)÷2=100

问题描述:

3X+(100-X)÷2=100

3X+(100-X)÷2=100 两边同时乘以2得
6x+(100-x)=200
6x+100-x=200
5x+100=200
5x=200-100
5x=100
x=100÷5
x=20