x²+y²+4x-6y+13＝0(x+2)^2+(y-3)^2=0x+2=0，y-3=0x=-2，y=3x^y=(-2)^3=-8
x²+y²+4x-6y+13＝0x²+4x+4+y²-6y+9＝0(x+2)²+(y-3)²=0所以x=-2，y=3x的y次方的值 =-8
