The explicit rule is an = a1 + 12 * (n - 1).
From the recursive rule, we can tell that each term is 12 more than the previous term, so we can write a1 + 12 * n.
However, if that's the rule, then when a1 is plugged in, it doesn't work. So, we must do 12 * (n - 1) to make it work.
Therefore, the explicit rule is:
an = a1 + 12 * (n - 1).