Answer:
B
Explanation:
The distributive property states that:
a(b + c) = ab + ac
Look at the choices:
A: 39 + 9 = 45
There's nothing of this form; in fact, there aren't even any parentheses, so eliminate A.
C: 36 times 9 = 9 times 36
This is saying 36 * 9 = 9 * 36. Again, there aren't any parentheses. Actually, this demonstrates the commutative property.
D: (12 + 3)3 = 3(12 + 3)
There are parentheses, but they're on both sides, so this can't be right, either. In fact, this is the associative property.
By elimination, the answer is thus B.