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.
7y - 4.5 - 6y
In this case, we have two y-terms and one constant.
Only the y-terms can be combined, so to simplify the expression we will rearrange it according to the Distributive Property to combine the like terms.