SOLUTION: Factor to find the center and radius of the given equation: a) x^2+y^2-8x=65 I understood how to solve this question and it came out to (x+4)^2+y^2=81 r=9 and (h.k)=(4,0) My q

Algebra ->  Coordinate-system -> SOLUTION: Factor to find the center and radius of the given equation: a) x^2+y^2-8x=65 I understood how to solve this question and it came out to (x+4)^2+y^2=81 r=9 and (h.k)=(4,0) My q      Log On


   



Question 861325: Factor to find the center and radius of the given equation:
a) x^2+y^2-8x=65
I understood how to solve this question and it came out to (x+4)^2+y^2=81
r=9 and (h.k)=(4,0)
My question is how to solve this next one.
b) x^2+y^2-4x+14y=-17
I don't understand why there is a "14y" and what I am suppose to do with it.
I first began by subtracting 10 from "14y" and "-17" and it came out to
(x+2)^2+(y-2)^2=-27. I don't believe it is correct though because I cannot square -27 to get the radius. Should I add 50 to both sides instead to receive 47 as the radius? So confused...

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
x^2+y^2-4x+14y=-17
x^2-4x+y^2+14y=-17
complete the square for x and for y
x^2-4x+4+y^2+14y+49=-17+4+49
(x-2)^2+(y+7)^2=36