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5 votes
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

2 Answers

4 votes

The answer is B, I have just confirmed it.

User Nicola Ambrosetti
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6.8k points
4 votes
It's a geometric progression where

a=-3\\ r=5


a_n=ar^(n-1)\\ a_n=-3\cdot5^(n-1)

User Shreyj
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7.1k points