Answer:
D.
Explanation:
The first expression for each set is using the distributing propety. We can start with the first one. We notice right away that 3 sets of 3y is 9y, when the other expression is 6. So, that is incorrect. Next we see the second one does have a correct y-value, but the integer value of 6 is not the same, since 3*3=9, not 6. For C we can tell that 9*3=27, which is not equal to 12. Therefore, D must be the answer.