Question

How to rewrite x2+y2-4x+12y-20

Answer 1

You could add the common variables together, to get -2x+14y-20, I'm not sure of any other ways to answer this, I'm sorry. I hope this helps tho

Answer 2

Assuming you are trying to find what kind of figure this represents, also that this = 0,

x^2 -4x       + y^2 +12y      =20
Completing the square for both x and y,
x^2 -4x +4 + y^2 +12y +36=20 + 4 + 36 = 60
(x-2)^2 + (y+6)^2 = 60
is a circle with center at (-2,6) with a radius of the square root of 60 or 2SQRT(15)