Write the explicit formula for the geometric sequence represented by the recursive formula.
a1 = 4
an = 5 · an-1
a) an = 4 · 5n
b) an = 5 · 4n
c) an = 4 · 5n-1
d) an = 5 · 4n-1

Option C is correct.

Explanation:

Explicit formula for the geometric sequence is given by:

where r is the common ratio

Given the recursive formula for geometric sequence:

For n =2

⇒

For n =3

⇒

Common ratio(r):

⇒ r = 5

Therefore, the explicit formula for the geometric sequence represented by the recursive formula is:

1/3 + 1/5 = 8/15.

step-by-step explanation:

hope it

i'm assuming that it's c.)   volcanoes built the mountains and earthquakes tore them down.