Question

Find a recursive rule for the nth term of the sequence. 5, 20, 80, 320, ...

Answer 1

Answer:

$a_1 = 5$

$a_n = 4a_{n - 1}$

Step-by-step explanation:

$a_1 = 5$

20/5 = 4

80/20 = 4

320/80 = 4

This a geometric sequence with r = 4.

$a_n = 4a_{n - 1}$

Answer:

$a_1 = 5$

$a_n = 4a_{n - 1}$