x^2+2x-y^2+6y-8=0<=====>x^2+2x+1=y^2-6y+9<=====>(x+1)^2=(y-3)^2<=====>|x+1|=|y-3|因为x+y≠2所以x+1=y-3所以x-y=-4
x^2+2x-y^2+6y-8=0(x+1)^2=(y-3)^2|x+1|=|y-3|x-y=-4