Question

Find an explicit rule for the nth term of the sequence. -3, -15, -75, -375, ...

an = 5 • -3n + 1
an = -3 • 5n - 1
an = 5 • -3n
an = -3 • 5n

Answer 1

It's a geometric progression where
$a=-3\\ r=5$

$a_n=ar^{n-1}\\ a_n=-3\cdot5^{n-1}$

Answer 2

The answer is B, I have just confirmed it.