{2x%=y%=1.5,x/2+y/7=30 就今晚

问题描述:

{2x%=y%=1.5,x/2+y/7=30 就今晚

2x+y=150
7x+2y=520
y=150-2x
7x+2(150-2x)=420
7x+300-4x=420
3x=120
x=40
y=70