x-y=1x=y+1
2x-3y=-8
2(y+1)-3y=-8
-y=-10y=10
2x-30=-8
x=12
3x-4y-1=0
2x-y-8=0y=2x-8
3x-4(2x-8)-1=0
-5x=31x=-31/5
y=-62/5-8=-102/5x-y=1,2x+3y=-8 还有这几题： 3x-4y+1=0,2x+y+8=0 题目错了x-y=1x=y+12x+3y=-82(y+1)+3y=-8 5y=-10 y=-2x=-2+1=-12x+y+8=0 y=-2x-83x-4y+1=03x-4(-2x-8)+1=011x+33=0 x=-3y=6-8=-2