Question

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

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

Answer 1

an = 5 • -3^n + 1

an = -3 • 5^n - 1

an = 5 • -3^n

an = -3 • 5^n

Answer 2

Each successive term differs by a factor of five:
-3
-3*5
-3*5*5
...
What does this look like?

Answer 3

an= -3 x 5^n-1

Answer 4

As long as you mean
\[-3 \times5^{n-1},\text{ and not }-3\times5^n-1,\]
then yes, you're right.

Answer 5

ok thank you