{(x-2)(y+3)=(x+1)(y-1)
{(x+1)(y+1)=(x-1)(y+5)
{xy+3x-2y-6=xy-x+y-1
{xy+x+y+1=xy+5x-y-5
{4x-3y=5 (1)
{4x-2y=6 (2)
(1)+(2)
-y=-1
y=1
4x=5+3y
4x=5+3
4x=8
x=2
方程组的x=2,y=-1