## Introductory Algebra for College Students (7th Edition)

$2x(3x-1)(3x+1)$
Factor out $2x$ to obtain: $=2x(9x^2-1)$ Write $9x^2$ as $(3x)^2$ to obtain: $=2x[(3x)^2-1]$ The binomial is a difference of two squares. RECALL: A difference of two squares can be factored using the formula: $a^2-b^2=(a-b)(a+b)$ Factor the difference of two squares using the formula above with $a=3x$ and $b=1$ to obtain: $=2x(3x-1)(3x+1)$