The formula of a circle is [tex](x-h)^{2} + (y-k)^{2} = r^{2} [/tex] where h = the x-value of the center of the cirlce, k = the y-value of the center of the circle, and r = the radius of the circle.
I'm guessing by the description the "9-5" are the coordinates of the circle in which case they belong in this format: (9, 5). I'm going to use this in the equation.
From here just plug in and simplify.
[tex] (x-9)^{2} + (y-5)^{2} = 12^{2} [/tex]
Your simplified answer is [tex] (x-9)^{2}+(y-5)^{2} = 144[/tex]
