已x²+2x-y²+6y-8=0,且x+y≠2,求x-y
问题描述:
已x²+2x-y²+6y-8=0,且x+y≠2,求x-y
答
x²+2x-y²+6y-8=0
(x+1)²-(y-3)²=0
x+1=0
y-3=0
x=-1
y=3
x-y=-1-3=-4