Answer
$a_n = a_{n - 1} + 9$, where $a_1 = -2$
Work Step by Step
In a recursive formula, we need to give the initial condition, $a_1$, which is the first item in the sequence:
$a_1 = -2$
To find the recursive formula of the sequence, we must first find the pattern:
$7 - (-2) = 9$
$16 - 7 = 9$
$25 - 16 = 9$
In this exercise, a term $a_n$ is found by adding $9$ to the previous term, $a_{n - 1}$:
$a_n = a_{n - 1} + 9$
