SOLUTION: In the standard (x,y) coordinate plane, what are the coordinates of the center of the circle whose equation is x^2 - 8x + y^2 + 10y + 15 = 0?

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Question 1084547: In the standard (x,y) coordinate plane, what are the coordinates of the center of the circle whose equation is x^2 - 8x + y^2 + 10y + 15 = 0?
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
Complete squares.
x%5E2-8x%2By%5E2%2B10y%2B15=0
x%5E2-8x%2By%5E2%2B10y=-15
x%5E2-8x%2B4%5E2%2By%5E2%2B10y%2B5%5E2=-15%2B4%5E2%2B5%5E2
%28x-4%29%5E2%2B%28y%2B5%29%5E2=-15%2B16%2B25
%28x-4%29%5E2%2B%28y%2B5%29%5E2=26
That last equation tells you that any point P%28x%2Cy%29 that satisfies that equation
is at a distance sqrt%2826%29 from point C%284%2C-5%29 ,
which is the center of the circle.