To simplify the expression 9(712) + 3(712), you can factor out 712:
9(712) + 3(712) = (9 + 3)(712) = 12(712).
Now, let's calculate 12(712):
12 * 712 = 8544.
Out of the responses you provided, none of them seem to match this numerical result. Please clarify or check the responses.