Chapter 4 - Polynomials - 4.7 Polynomials in Several Variables - 4.7 Exercise Set - Page 284: 31

$6a^2c-5ab^2+a^2b-2ab^2$

By combining like terms, the given expression, $ 5a^2c-2ab^2+a^2b-3ab^2+a^2c-2ab^2 ,$ simplifies to \begin{array}{l}\require{cancel} (5a^2c+a^2c)+(-2ab^2-3ab^2)+a^2b-2ab^2 \\\\= 6a^2c-5ab^2+a^2b-2ab^2 .\end{array}