SOLUTION: how do you find the center and radius for this equation for a circle x^2+y^2-18x-18y+53=0

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Question 285141: how do you find the center and radius for this equation for a circle
x^2+y^2-18x-18y+53=0
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
complete the squares

(x^2 - 18x + 81) + (y^2 - 18y + 81) = -53 + 81 + 81

(x - 9)^2 + (y - 9)^2 = 109

center ___ (9,9)

radius ___ sqrt(109)