Respuesta :

I hope this helps you



x^2-4x+4+y^2+2y+1-16=0


(x-2)^2+(y+1)^2=16


x=2


y= -1
complete the square on the terms in x and y:-

(x - 2)^2 + (y + 1)^2   - 4 - 1 - 11 = 0
(x - 2)^2 + (y + 1)^2  = 16 

So the centre is at (2,-1)  and the radius = sqrt 16 = 4