Ur almost right, but ur forgetting a thing about PEMDAS. Parenthesis, Exponents, Multiplication/Division, and Addition/Subtraction. The reason why u pair MD and AS together is because order of operations states that M and D have the same order, following with A and S, so you would do them in the order they come in the prolem, from left to right. In this case, you would divide add 2+1, then divide 6 by 2, and then multiply whats left of these answers (3×3), giving you 9.