若x*x+y*y-4x+16y+13=0 ,则x=____ y=____
问题描述：
若x*x+y*y-4x+16y+13=0 ,则x=____ y=____
答
x*x+y*y-4x+6y+13=0
(x^2-4x+4)+(y^2+6y+9)=0
(x-2)^2+(y+3)^2=0
x-2=0,y+3=0
x=2,y=-3