SOLUTION: center and radius of x^2 +y^2-18x+8y+81=0 please

Question 434811: center and radius of x^2 +y^2-18x+8y+81=0 please

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
center and radius of x^2 +y^2-18x+8y+81=0 please
Complete the square on the x-terms and on the y-terms:
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x^2-18x+81 + y^2+8y+16 = -81+81+16
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(x-9)^2 + (y+4)^2 = 16
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Center at (9,-4)
Radius = sqrt(16) = 4
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Cheers,
Stan H.
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