Answer:
[tex]a_{n}[/tex] = 16 - 7n
Step-by-step explanation:
There is a common difference between consecutive terms , that is
2 - 9 = - 5 - 2 = - 12 - (- 5) = - 7
This indicates the sequence is arithmetic with nth term
[tex]a_{n}[/tex] = a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = 9 and d = - 7 , then
[tex]a_{n}[/tex] = 9 - 7(n - 1) = 9 - 7n + 7 = 16 - 7n