Question

Help on number 12 please?​

Answer 1

Answer:

f(n)= 5 · 4

$f(n) = 5 \times 4 ^{n - 1}$

Step-by-step 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.