Question

Find an explicit rule for the nth term of the sequence.

-3, -15, -75, -375, ...

Answer 1

• a(n) = -3*5^(n-1)

Explanation:

Given sequence

• -3, -15, -75, -375, ...

This is a GP with

• The first term = -3
• Common ratio = 5

Formula for nth term is:

• a(n) = -3*5^(n-1)