SOLUTION: find the center and radius of the circle given by: x^2+10x+y^2+12y=-12

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Question 136438: find the center and radius of the circle given by:
x^2+10x+y^2+12y=-12
Answer by Earlsdon(6291) About Me  (Show Source):
You can put this solution on YOUR website!
The general form for a circle with center at (h, k) and radius r is:
%28x-h%29%5E2%2B%28y-k%29%5E2+=+r%5E2
In your equation:
x%5E2%2B10x%2By%5E2%2B12y+=+-12 First complete the squares in the x-terms and in the y-terms.
%28x%5E2%2B10x%2B25%29%2B%28y%5E2%2B12y%2B36%29+=+25%2B36-12 Factor the left side and simplify the right side.
%28x%2B5%29%5E2+%2B+%28y%2B6%29%5E2+=+48 Compare this with the general form:
%28x-h%29%5E2%2B%28y-k%29%5E2+=+r%5E2
h+=+-5, k+=+-6, and r+=+sqrt%2848%29
Center is at: (-5, -6) and the radius is, r+=+4sqrt%283%29