Question

Help on number 12 please?​

Answer 1

f(n)= 5 · 4

`f(n) = 5 * 4 ^(n - 1)`

Explanation:

You use the explicit formula for geometric sequence. The five is the firat term and is placed correctly. The 4 is the rate of change, because if you multiply 5 by 4 you get 20 and so on.