Question

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

-5, -25, -125, -625, ...

Answer Choices

A) an = -5 • 5n
B) an = 5 • -5n + 1
C) an = 5 • -5n
D) an = -5 • 5n - 1

Answer 1

This is a GS with first term -5 and common ratio = 5.
an = a1. r^(n -1)
= -5 . 5^(n - 1)

Its D