[x+3y=65,2x+2y=90]
问题描述:
[x+3y=65,2x+2y=90]
答
x+3y=65
x=65-3y
2x+2y=90
2(65-3y)+2y=90
130-6y+2y-90=0
4y=40
y=10
x=65-30=35