Final answer:
The next 3 terms in the sequence are -3, 6, and 15.
Step-by-step explanation:
To find the next 3 terms in the sequence, we can use the recursive formula an = an-1 + 9.
Starting with the first term, which is -12, we can substitute this value into the formula to find the second term: a2 = a1 + 9 = -12 + 9 = -3.
Continuing this process, we can find the next terms: a3 = a2 + 9 = -3 + 9 = 6, a4 = a3 + 9 = 6 + 9 = 15, and a5 = a4 + 9 = 15 + 9 = 24.
Therefore, the next 3 terms in the sequence are -3, 6, and 15.