Marina solved the quadratic equation 9x^2 - 36x - 720 = 0 by completing the square. In the process, she came up with the equivalent equation
(x + r)^2 = s
where r and s are constants. What is s?
+2666 Divide by 9: \(x^2 - 4x - 80 = 0 \)
Complete the square on the left: \((x-2)^2 - 84 = 0 \)
Add 84 to both sides: \((x-2)^2 = 84\)
So, \(s = \color{brown}\boxed{84}\)
