2/5*X-3/5*(X-2/5*X)/(1+3/5)=56

问题描述:

2/5*X-3/5*(X-2/5*X)/(1+3/5)=56

(2/5)X-(1-2/5)X/(1+3/5)=56
0.4X-0.4X/1.6=56,
0.4X-0.25X=56,
0.15X=56,
X=56/0.15
=56/(3/20)
=56*20/3
=1120/3.