Question

8. John is in a club that collects annual dues. In the first year that he was a member, he paid $20 in club dues. However, the club dues increase by $2 each year. Identify the function that describes the relationship between the number of years that John has been a member of the club and the dues he pays that year.

options:
A. f(n) = 20 + 2(n – 2)
B. f(n) = 20 + 2(n + 1)
C. f(n) = 20 + 2(n – 1)
D. f(n) = 20 + 2n

Answer 1

C f(n) = 20 + 2(n – 1)

Explanation:

got it right on test

Answer 2

Answer: C) f(n) = 20 + 2(n - 1)

Explanation:

The explicit formula is:
`a_n=a_1+d(n-1)` where

• 
  `a_1` is the first term
• d is the difference between consecutive terms

Given: In the first year he paid $20 -->
`a_1` = 20

Dues increase $2 each year --> d = 2

`a_n` = 20 + 2(n - 1)