x-3y=2
y=x
y-3y=2
y=-1=x
2 x+y=5 2x+y=8
x=5-y 2(5-y)+y=8
10-2y+y=8
y=2 x=5-y=3
3 4x+3y=5 x-2y=4
x=2y+4 4(2y+4)+3y=5
11y=-11 y=-1 x=2y+4=2
4 m-n/2=2 m+2n=12
m=n/2+2 n/2+2+2n=12
5n/2=10 n=4 m=n/2+2=4第四题错了哪里错了呢m-n/2=2 m+2n=12m=n/2+2 n/2+2+2n=12 5n/2=10n=4m=4/2+2=4指一下