X=-1-2Y,带入计算就好拉
Y^2-Y-2Y^2-4-8Y+6Y+2=0
-Y^2-3Y-2=0
Y^2+3Y+2=0
(Y+3/2)^2-9/4+4=0
(Y+3/2)^2=1/4
|Y+3/2|=1/2
Y=-1所以X=1
或者X=3Y=-2
完整且正确,给我分吧.PS：|Y-3/2|是绝对值