SOLUTION: Please answer: Give the center and radius of the circle: {{{X^2+y^2+6x+5y=0}}}

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Question 687905: Please answer:
Give the center and radius of the circle:
X%5E2%2By%5E2%2B6x%2B5y=0
Answer by fcabanski(1391) About Me  (Show Source):
You can put this solution on YOUR website!
The general formula for a square is %28x-h%29%5E2+%2B+%28y-k%29%5E2+=+r where (h,k) is the center and r is the radius. To convert the given formula into the general circle formula, you complete the square.


Write the equation with x and y terms grouped: %28x%5E2+%2B+6x%29+%2B+%28y%5E2+%2B5y%29+=+0


For x and y parts, take 1/2 of the coefficient of the non squared term, square it, add it on both sides. %28x%5E2+%2B+6x+%2B+9%29+%2B+%28y%5E2+%2B+5y+%2B6.25%29+=+9%2B6.25


Write each (the x and y part) in squared form: %28x%2B3%29%5E2+%2B+%28y%2B2.5%29%5E2+=+15.25----> %28x-%28-3%29%29%5E2+%2B+%28y-%28-2.5%29%29%5E2+=15.25


The radius is 15.25. The center is (-3, -2.5)

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