Find the radius of the circle with equation x^2 - 4x + y^2 - 6y - 36 = 25
Put it into standard form by completing the square for x and y
x^2 - 4x + y^2 - 6y = 25 + 36
(x-2)^2 +( y-3)^2 = 25 + 36 + 4 + 9 The right side = radius ^2
= 74 radius = sqrt 74 = 2 sqrt 19
+36916 
