Combine the like terms to make a simpler expression:

-n + (-3) + 3n + 5

Like terms are terms that have the same variable. In this equation, your like terms are terms with n and terms without n. Put the like terms next to each other in the expression.

-n + 3n + (-3) + 5

Now, combine - n and 3n the same way you would combine - 1 and 3.

2n + (-3) + 5

Next, combine - 3 and 5.

2n + 2

Since 2n and 2 aren't like terms, your final answer will be 2n + 2.