Answer:
8a
Step-by-step explanation:
When you have like terms with a variable, you add the bases of the terms to simplify.
In the case of 5a+3a, you would add 5 and 3 to get 8, then reattach the variable, a, to the base.
That gives you 8a, the simplified answer.
I hope this helps :) if so, brainliest would help me out a lot <3