Find the radius of the circle with equation x^2 + y^2 = 6x + 8y.
Put it into standard circle form (x-h)^2 + (y-k)^2 = r^2
x^2 - 6x + y^2 -8y = 0 complet ehte square for 'x' and 'y'
(x-3)^2 + (y-4)^2 = 9+16 = 25 soooooo r^2 = 25 r = 5
+36915 
