(25-X)÷(30-X)=4分之3
问题描述:
(25-X)÷(30-X)=4分之3
答
(25-X)÷(30-X)=4分之3
3(25-X)=4(30-X)
75-3X=120-4X
4X-3X=120-75
X=25