What happens to the value of the expression n+15 as n decreases?

Hello! 

As the variable n decreases in size, the value of the given expression will decrease in size as well.

For example, let's say that n=22. When you add 22 to 15, you'll get 37 as your answer. Let's say that n decreases by 1 every time you use it in the given expression. Now n=21. When 21 is added to 15, your answer is 36. As you can see, the value of the expression had decreased as the value of n decreased.

I hope this helps! :)

The answer is part a: use