## Intermediate Algebra (6th Edition)

$x^{2}-9y^{2}$
$(x+3y)(x-3y)$ Special product: $a^{2}-b^{2}$ Substitute: $a=x$ and $b=3y$ $(x)^{2}-(3y)^{2}$ Simplify $x^{2}-9y^{2}$