SOLUTION: x^2+y^2+2x-4y-4=0 complete square and state the center and the radius or the circle

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Question 200112: x^2+y^2+2x-4y-4=0 complete square and state the center and the radius or the circle
Answer by orca(409) About Me  (Show Source):
You can put this solution on YOUR website!
First moving the constant term to the right side, we have
x%5E2%2By%5E2%2B2x-4y=4
Re-arranging the terms on the left side, we get
x%5E2%2B2x%2By%5E2-4y=4
Add 1 and 4 to both sides, we have
x%5E2%2B2x%2B1%2By%5E2-4y%2B4=4%2B1%2B4
%28x%2B1%29%5E2%2B%28y-2%29%5E2=9
%28x%2B1%29%5E2%2B%28y-2%29%5E2=3%5E2
So the center of the circle is (-1, 2). The radius is 3.