## College Algebra (10th Edition)

$3(1-3x)(1+3x)$
Factor out $3$ to obtain: $=3(1-9x^2) \\=3[1^2-(3x)^2]$ RECALL: $a^2-b^2=(a-b)(a+b)$ Use the formula above with $a=1$ and $b=3x$ to factor the binomial and obtain: $=3(1-3x)(1+3x)$