SOLUTION: Appreciate any help on this problem: Give the center and radius of the circle {{{x^2+y^2+6x-8y-56=0}}} I think the center is (3,4) but I wasn't sure about the radius. I would

Algebra ->  Coordinate-system -> SOLUTION: Appreciate any help on this problem: Give the center and radius of the circle {{{x^2+y^2+6x-8y-56=0}}} I think the center is (3,4) but I wasn't sure about the radius. I would      Log On


   



Question 182142: Appreciate any help on this problem:
Give the center and radius of the circle x%5E2%2By%5E2%2B6x-8y-56=0
I think the center is (3,4) but I wasn't sure about the radius. I would appreciate any step by step help.
Thanks!

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Give the center and radius of the circle x%5E2%2By%5E2%2B6x-8y-56=0
I think the center is (3,4) but I wasn't sure about the radius. I would appreciate any step by step help.
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x^2+y^2+6x-8y-56=0
Complete the square on the x and on the y terms to get:
x^2 + 6x + ? + y^2 - 8y + ? = 56 + ?
x^2 + 6x + 9 + y ^2 - 8y + 16 = 56 + 9 + 16
(x+3)^2 + (y-4)^2 = 81
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Center is (-3,4); radius = sqrt(81) = 9
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Cheers,
Stan H.