Recently there have been a rash of questions of the form "What is 48/2(9+3)?", the most recent of which being here (and other examples are linked to in mixedmath's answer). I think most of us can agree that this really isn't a math question, merely an issue about poor communication. But this is actually a common question on the internet, and a lot of people are genuinely confused about it. I think this confusion in fact stems from a larger misconception that math is about manipulating symbols which have no real meaning, and that perhaps these questions could be a valuable opportunity to help dispel this misconception. However, they certainly can be annoying and their repeated asking does warrant closure under Math.SE's rules. So what should we do about them?
This question should be added to the list of generalizations of common questions, and a definitive answer should be given to it. Then we can close all the others as duplicates of one answer.
Perhaps the FAQ should be updated to contain some information about order of operations type questions and have a link to a thread where an example problem like the one you stated is answered. I've seen these types of questions popping up in other random places, like facebook so I wouldn't be surprised if they continued to pop up here. Other than that, I'd just suggest voting to close these types of questions and linking the askers to a thread where this question is adequately answered.