Mary is n years old. What expression represents her age 5 years from now? 5 years ago?

After 5 years : (n + 5) years!

Before 5 years : (n - 5)

Step-by-step explanation:

Given the age of Mary is n years old

After 5 years, She must be 5 years more from now so,

Her age will be (n + 5) years after 5 years from now!

Also, 5 years ago she must be 5 years less than from now,

So, her age 5 years ago was (n - 5) years!