Chapter R - Elementary Algebra Review - R.4 Polynomials - R.4 Exercise Set - Page 961: 52

$a^5b+a^2b^3-a^3b^2-2a^2b^2$

Using the Distributive Property, the given expression, $ a^2b(a^3+b^2-ab-2b) ,$ is equivalent to \begin{array}{l}\require{cancel} a^2b(a^3)+a^2b(b^2)+a^2b(-ab)+a^2b(-2b) \\\\= a^5b+a^2b^3-a^3b^2-2a^2b^2 .\end{array}