<PRE><B>Question 749798</B>
find the center of circle with these three points (-1,3) (-13,3) (-7,9)
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A(-1,3) B(-13,3) C(-7,9)
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	X	Y	x^2+y^2	Coeff
Point 1	-1	3	10	1
Point 2	-13	3	178	1
Point 3	-7	9	130	1
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Using the matrix above, the center is at (-7,3)
-72(x^2+y^2) - 1008x + 432y = 1584
x^2 + 14x + y^2 - 6y + 72 = 0
(x+7)^2 + (y-3)^2 = 36</PRE>