D. f(n) = 80 + (n - 1)100
In this situation, the initial deposit was $100 and an additional $80 was added each year. This can be represented by an arithmetic sequence where the first term is $100 and the common difference is $80.
The formula for an arithmetic sequence is:
An = a1 + (n-1)d
Where:
An = the nth term of the sequence
a1 = the first term of the sequence
n = the term number
d = the common difference
Substitute a1 = 100, d = 80, and simplify:
An = 100 + (n-1)80
An = 100 + 80n - 80
An = 80 + 80n
Therefore, the correct function that models this situation is f(n) = 80 + (n - 1)100.
On Roy's first birthday, his grandfather placed $100 in a bank account. On Roy's second birthday, his grandfather placed $80 in the account and continued to place $80 each passing year. The arithmetic sequence 100, 180, 260, 340,… indicates the account balance for the first four years. Create a function that models this situation.
A. f(n) = 80(100)^n-1
B. f(n) = 100 + (n - 1)80
C. f(n) = 100 + 80(n)
D. f(n) = 80 + (n - 1)100
1 answer