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

$x=4$ or $x=9$
$x^{2}-13x=-36$ Adding $36$ to both sides, $x^{2}-13x+36=-36+36$. Simplifying, $x^{2}-13x+36=0$. $x^{2}-4x-9x+36=0$ $x(x-4)-9(x-4)=0$ $(x-4)(x-9)=0$ $(x-4)=0$ or $(x-9)=0$ $x=4$ or $x=9$