## Algebra: A Combined Approach (4th Edition)

$x^2 -9x + 20 = 0$
the equation $(x-4)(x-5) = 0$ has the answers 4,5 therefore lets multiply, $x^2 -4x - 5x + 20 = 0$ $x^2 -9x + 20 = 0$ has the answers 4,5