## Functions Modeling Change: A Preparation for Calculus, 5th Edition

$$\left(x-3+2z\right)\left(x-3-2z\right)$$
Factoring the expression completely, we find: $$\left(x-3\right)^2-4z^2 \\ \left(x-3+2z\right)\left(x-3-2z\right)$$