SOLUTION: Find the center and radius of the circle given by x^2+y^2-4x+8y=4

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Question 45671: Find the center and radius of the circle given by x^2+y^2-4x+8y=4
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
x^2+y^2-4x+8y=4
Rearrange and complete the square on the x and the y terms, as follows:
x^2-4x+4 + y^2+8x+16 = 4 + 4 + 16
Factor as follows:
(x-2)^2 + (y+4)^2 = 24
Center is at (2,-4)
radius is sqrt24 = 2sqrt6
Cheers,
Stan H.