Jaison N. answered 09/09/12
A PhD to Teach You Math
You have a problem in combining like terms. In this problem, there are two types of terms: those with an m in front of them and those that do not. There is one term with an m so leave that one alone. Now look for all terms that do not contain an m. There are two: the 7 and the 2. Now, the 7 is in a set of parenthesis. But, since there isn't anything in on either side of the parenthesis, you can remove the parenthesis so you have m + 7 + 2. Now, add the 7 and 2 and you have m + 9!
You can also think of it as (1)(m + 7) + 2 and distribute the (1). We call this the implied 1. It's in front of any term in any equation but we don't write it down because multiplying by 1 doesn't do anything.