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— can be combined.
6x^2 + 7 + 3x^2 + 1
In this case, we have two x^2-terms and two constants.
All terms can be combined, so to simplify the expression we will rearrange it according to the Commutative Property of Addition and then combine like terms.