Answer
$2b(a-3)(2a+5)$
Work Step by Step
Consider the polynomial $(4a^2b-2ab-30b)$
Take out common terms.
or, $=2b(2a^2-a-15)$
Apply rule of factorization.
$=2b(2a^2-6a+5a-15)$
$=2b[2a(a-3)+5(a-3)]$
Hence, $(4a^2b-2ab-30b)=2b(a-3)(2a+5)$