48÷2(9+3) = 288.
PEMDAS is Parenthesis, Exponents, Multiplication, Division, Addition and Subtraction. But when Multiplication and Division are present in an equation with no parenthesis you do whatever comes first (multiplication, or division) left to right. I don't know if this is some really annoying way of "trolling", but for the love of god If people are seriously getting this wrong I've lost faith in whatever you people are doing in school.