x^2 – 20 = 8x. Finally we need to subtract 8x from both sides to get x^2 – 8x – 20 = 0 Now we have a quadratic equation to solve by factoring and using the zero factor.
(x-)(x+) = 0. Since the coefficient of x^2 is 1 we can start with a pair of parenthesis with an x in each. Since the 20 is negative we know there