Both answers are technically right, because the equation is written incorrectly.
The question really is, did the person mean
48
---
2(9+3)
or
48
--- (9+3)
2
The way it stands right now the equation is missing a set of brackets. So you guys are just going to argue until your face is blue.
http://www.google.com/#s&q=%2248%C3%...2B3%29%22&fp=1