What is the explicit rule for this sequence?

-5, 15, - 45, 135, ...

Step-by-step explanation:

In a geometric sequence, consecutive terms differ by a common ratio. The formula for determining the nth term of a geometric progression is expressed as

an = a1r^ (n - 1)

Where

a represents the first term of the sequence.

r represents the common ratio.

n represents the number of terms.

From the given sequence,

a1 = - 5

r = 15 / - 5 = - 3

Therefore, the explicit rule for this sequence is

an = - 5 ( - 3) ^n - 1