Many people will get 2.

Subtraction is the same as adding the additive inverse (the opposite) and division is the same thing as multiplying by the multiplicative inverse (the reciprocal).

Therefore, 48/2(9+3) is 48*.5*(9+3) which is 24*12 = 288. (.5 is the reciprocal of 2)

When using the PEMDAS convention, M and D are done simultaneously left to right because multiplication is commutative and since D is really M by the reciprocal. When using the PEMDAS convention, A and S are done simultaneously left to right because addition is commutative and since S is really A of the opposite.

Every expression can be re-written to not use division and to not use subtraction. You'll have multiplication by the reciprocal and adding the opposite. When doing that, PEMDAS simplifies to PEMA.