(2/5)X-(1-2/5)X/(1+3/5)=56
问题描述:
(2/5)X-(1-2/5)X/(1+3/5)=56
答
(2/5)X-(1-2/5)X/(1+3/5)=56
(2/5)*x-3/5*x/(8/5)=56
(2/5)*x-(3/5)*(5/8)*x=56
(2/5)*x-(3/8)*x=56
(16/40)*x-(15/40)*x=56
(1/40)*x=56
x=56*40=2240