已知x^2+2x+y^2-6x+10=0,则x+y的值是?

已知x^2+2x+y^2-6x+10=0,则x+y的值是?
已知x^2+2x+y^2-6x+10=0,则x+y的值是?

已知x^2+2x+y^2-6x+10=0,则x+y的值是?
x^2+2x+y^2-6x+10=0
(x+1)^2+(y-3)^2=0
x=-1,y=3
x+y=-1=3=2

貌似：x^2+2x+y^2-6y+10=0,
x^2+2x+1+y^2-6y+9=0,
(x^2+2x+1)+(y^2-6y+9)=0
(x+1)^2+(y-3)^2=0
所以x+1=0,y-3=0,
x=-1，y=3
所以x+y=-1+3=2