Answer
$\color{blue}{(5a-3)(2b+7)}$
Work Step by Step
Regroup:
$=(10ab-6b)+(35a-21)$
Factor out $2b$ in the first and $7$ in the second group to obtain:
$=2b(5a-3)+7(5a-3)$
Factor out $5a-3$ to obtain:
$=\color{blue}{(5a-3)(2b+7)}$