For this question, we need to simplify the expression, and to do this, we first should rearrange the way it is written, so similar (or like) terms are next to each other. So in rearranging the expression we get this: 5a - a + 2 + 9Now we can see that it is easier to simplify the expression. 5a-a can be simplified to 4a, and 2+9 can be simplified to 11, and combining these two simplifications we get 4a+11.