The equation x2+y2+10x−8y=59 can be written in the form (x−h)2+(y−k)2=r2, where h,k, and r are integers. Find the value of r2.
x^2 + 10x + y^2 - 8y = 59 complete the square on x, y
x^2 + 10x + 25 + y^2 - 8y + 16 = 59 + 25 + 16
(x + 5)^2 + ( y - 4)^2 = 100
r^2 = 100
+363 
