x^2+2x+1+y^2-8y+16=0、y/x.十万火急!

x^2+2x+1+y^2-8y+16=0、y/x.十万火急!

x^2+2x+1+y^2-8y+16=0
(x+1)^2+(y-4)^2=0
x=-1,y
y/x=-4