Answer: 13
Step-by-step explanation: In this problem we're asked to rewrite as addition and then evaluate.
It's important to understand that minus a negative means the same thing as plus a positive so we can change 5 - (-8) to 5 + (+8).
Now we can simply add to get a sum of 13.
Therefore, 5 - (-8) or 5 + (+8) = 13