已知x2+4y+y2+2y+5=0,则x的y次方=?
问题描述：
已知x2+4y+y2+2y+5=0,则x的y次方=?
答
x^2+4x+y^2+2y+5=0
x^2+4x+4+y^2+2y+1=0
(x+2)^2+(y+1)^2=0
(x+2)^2=0,(y+1)^2=0
x=-2
y=-1
x^y
=(-2)^(-1)
=(-1/2)^1
=-1/2