Elementary Algebra

$7ab(2ab^2+5b-7a^2)$
Factoring the $GCF= 7ab ,$ the given expression, $14a^2b^3+35ab^2-49a^3b ,$ is equivalent to \begin{array}{l}\require{cancel} 7ab(2ab^2+5b-7a^2) .\end{array}