## Intermediate Algebra (12th Edition)

$2(3a+7b)(3a-7b)$
$\bf{\text{Solution Outline:}}$ To factor the given expression, $18a^2-98b^2 ,$ factor first the $GCF.$ Then, use the factoring of the difference of $2$ squares. $\bf{\text{Solution Details:}}$ Factoring the $GCF= 2 ,$ the expression above is equivalent to \begin{array}{l}\require{cancel} 2(9a^2-49b^2) .\end{array} Using $a^2-b^2=(a+b)(a-b)$ or the factoring of the diffrence of $2$ squares, the factored form of the expression above is \begin{array}{l}\require{cancel} 2(3a+7b)(3a-7b) .\end{array}