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The circle $x^2-y^2 + ax -2y -15 = 0$ contains the point $P(-6, 5)$. How would I find a?

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up vote 4 down vote accepted

You let $x=-6$ and $y=5$ in your equation for the circle. Then solve for $a$.

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Thank you very much – Rollo Montgomery Konig-Brock Jan 18 '12 at 1:20

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