to clarify: PEMDAS is the order of operations. so parenthesis first: 48÷2(9+3) = 48÷2(12) then multiplication and division (they have the same precedence): 48÷2(12) = 24*12 = 288
for another reference: http://www.google.com/search?q=48%C3%B72(9%2B3)
http://www.physicsforums.com/showthread.php?p=3235154
Anyway, the answer depends completely on whether you believe that multiplication by juxtaposition has the same precedence as multiplication by explicit symbol. There're good reasons to believe it doesn't, eg. the first post on that linked thread, but whatever the answer, it's entirely based on typographical convention. I don't work in the community that cares, so I don't really have an opinion, other than to point out it's not as cut-and-dried as virtually ever poster here believes.
In the community that I do work, people who write parsers, things like this have to be explicitly specified. That's why I maintain that the correct answer is "syntax error".
sent frim my drunk phone