Answer:
I think they took 3 * 3 is equals to 9
3 * 5 equals to 15
3 * 7 equals to 21
and 3 * 9 equals to 27.
Explanation:
can can you realise that they skipped 3 * 4 3 * 6 and 3 * 8 and the difference between 9 and 15 is 6 meaning there's a gap of 6 at each sequence so I guess my answer is 3 and + 3 if it's not if this is not the answer please tell me if it is not matching with your book tell me so that i can ask the people around me. answer 3n + 3