x²+y²-6x+10y+34=0x²+6x+9+y²-10y+25=0(x+3)²+(y-5)²=0x+3=0，y-5=0x=-3，y=5x+y=-3+5=2
x²+y²-6x+10y+34=0(x-3)^2+(y+5)^2=0x-3=0y+5=0x=3y=-5x+y=3-5=-2
(x-3)的平方+(y+5)的平方=0所以x=3,y=-5所以x+y=-2
