I'm assuming i can't have more than one discount - for instance, could you get an AP and AAA discount applied? Guessing not, but it doesn't hurt to ask, right?
You can only have 1 discount. If the AP rate is better than the AAA rate, then you would want to go with AP.
It's not like at a retail place where you get "x" % off with this one and then "x" % off with that one that you can combine. It's a set rate for the room for the night.