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.
-4b + (-9k) - 6 - 3b + 12
In this case, we have two b-terms, one k-term, and two constants.
The b-terms and constants can be combined, so to simplify the expression we will rearrange it according to the Commutative Property of Addition and then combine like terms.
