Which formula can be used to describe the sequence

-3, 3/5, - 3/25, 3/125, - 3/625

a (n) = - 3 (-1/5) ^ (n - 1)

Step-by-step explanation:

From the first term, - 3, we get the second term, 3/5, by multiplying - 3 by - 1/5.

Thus, the common ratio is - 1/5.

The general formula in this case is a (n) = (first term) (common ratio) ^ (n - 1), or

a (n) = - 3 (-1/5) ^ (n - 1)