$${ a }^{ 3 } b-a { b }^{ 4 } +5 { a }^{ 2 } b-5 { b }^{ 4 }$$
Factor
$b\left(a+5\right)\left(a^{2}-b^{3}\right)$
Solution Steps
Factor out $b$.
$$b\left(a^{3}-ab^{3}+5a^{2}-5b^{3}\right)$$
Consider $a^{3}-ab^{3}+5a^{2}-5b^{3}$. Do the grouping $a^{3}-ab^{3}+5a^{2}-5b^{3}=\left(a^{3}-ab^{3}\right)+\left(5a^{2}-5b^{3}\right)$, and factor out $a$ in the first and $5$ in the second group.
