3(x+y)+2(x-3y)=20,30%x+60%y=10%*60
问题描述:
3(x+y)+2(x-3y)=20,30%x+60%y=10%*60
答
3(x+y)+2(x-3y)=20
3x+3y+2x-6y=20
5x-3y=20 (1)
0.3x+0.6y=6 (2)
(2)×5+(1)
6.5x=50
x=100/13
y=(5x-20)/3=80/13