(1/4X+X-1/5)=X-1/5--30

问题描述:

(1/4X+X-1/5)=X-1/5--30

(1/4X+X-1/5)=X-1/5-30
1/4X+X-1/5=X-1/5-30
1/4X=-30
所以X=-120