Exercise 5 Page 278

In order to write the formulas for the given arithmetic sequence, we first need to find the common difference. We can do this by subtracting the first term of the sequence from the second term. The common difference is $\text{-}2.$ Let's now find the recursive formula and the explicit formula one at a time.

Recursive Formula

To write the recursive formula, we will use the general form for a recursive formula of an arithmetic sequence.