Question

a_n = 27 - 3(n - 1)
rewrite the explicit formula in function form
f(n) = 30n + 1
f(n) = -3n + 30
f(n) = 9n + 3
f(n) = -2n + 9

Explanation:

Step1: Expand the parentheses

$a_n = 27 - 3n + 3$

Step2: Combine constant terms

$a_n = -3n + (27 + 3)$

Step3: Rewrite as function form

$f(n) = -3n + 30$

Answer:

B. $f(n) = -3n + 30$