Simple expression. Just follow the Order of Operations. Here's the basic rules of the Order, there's more, but these are all the ones we need for this expression.
Rule 1: First perform any calculations inside parentheses.
Rule 2: Next perform all multiplications and divisions, working from left to right.
Rule 3: Lastly, perform all additions and subtractions, working from left to right.
(Credit to mathgoodies.com)
So, seeing how there's no parentheses, multiplications, or divisions, we solve the expression from left to right.
7 + 8 - 2
15 - 2
13
The answer is 13.
+16 
