2元一次方程组,X+2Y=5,2X-Y=3
问题描述:
2元一次方程组,X+2Y=5,2X-Y=3
答
X+2Y=5,2X-Y=3
x=5-2y代人2X-Y=3
2*(5-2y)-y=3
10-4y-y=3
-5y=-7
y=7/5
x=5-2*7/5
=2.2