The first step in simplifying this expression is to identify which, if any, terms can be combined. Remember, only like terms — constant terms or terms with the same variables and the same exponents — can be combined.
2h^3g + 3hg^3 + 7h^2g^2 + 5h^3g + 2hg^3
In this case, we have two h^3g-terms, two hg^3-terms, and one h^2g^2-term. Only the h^3g-terms and hg^3-terms can be combined, so to simplify the expression we will rearrange it according to the Commutative Property of Addition and then evaluate the difference between the like terms.
