How do you solve #x^2-8x=9# by completing the square?
Jul 7, 2015
Solve y = x^2 - 8x - 9 = 0
In this case, you don't need to solve by completing the squares.
Use the shortcut.
When (a - b + c = 0) --> 2 real roots: (-1) and (-c/a = 9).