The horizontal line is the archaic notation for parenthesis in modern form. You have inserted a set of parens where they did not exist before. ;-P
NO MORT YOU ARE WRONG ... it is an archaic form of the DIVIDED BY sign. Besides
2(9+3) is distributive principle learned in 4th grade
2*9+2*3 NOW muliply first is accurate
18+6=24
now 48Divided by 24 =2