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 variable and the same exponent — can be combined.
( 4x^2 + 9x + 1) + ( 2x^2 + 7x + 13)
In this case we have two x^2-terms, two x-terms, and two constants.
All of those can be combined, so to simplify the expression we will rearrange it according to the Commutative Property of Addition and then combine like terms.