The order of operations is:
P-parentheses. So you solve what is in the parentheses first, in this case (9+3) which equals 12, let's leave the 12 in parentheses for simplicity (will come in handy later on).
E-exponents. There are no exponents in this problem.
M&D-Multiplication and division. I put these together since one can switch positions in the order with the other depending on the situation. More on that later. In this case the division would come first (again more on that later) so it would be 48/2 which equals 24. This is where the multiplication comes in, this is also why we left the twelve in parentheses, it makes it simpler. Now you multiply the 12 by the 24 which gives you
288.
A&S There is only a little addition in the parentheses which I have already explained. Addition and subtraction can also swap places with each other depending on the situation.
Now for the part that it seems many people forget:
From Left To Right- Once you have the parentheses worked out then you solve the multiplication/division from left to right this is when multiplication and division can switch places depending on their location in the problem (for example: 6x6/2 would be solved by multiplying 6 and 6 together then dividing the resulting number (36) by 2 to get 18). After multiplication comes addition/subtraction again this is when they can swap places when you solve from left to right (example: 6+6-2 would be solved by adding 6 and 6 to get 12 and then subtracting 2 to get 10).
So the whole problem step by step in numbers:
1. 48/2(9+3)
2. 48/2(12)
3. 24(12)
4. 288
All the parentheses around the twelve do is serve as a multiplication sign really.
The problem can also be written as:
1. 48/2(9+3)
2. 48/2x12
3. 24x12
4. 288
So the correct answer is 288.
Just to double check:
http://www.google.com/search?q=48÷2(9+3)+&btnG=Search