Multiple choice

Find the first term of a sequence in which each term of the sequence is found by multiplying the previous term by $-3$ and the 8th term is $4374$.

  1. -0.222

  2. 0.667

  3. -2

  4. 6

  5. -18
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C Correct answer
Explanation

Geometric sequence: a * r^(n-1) = term. a * (-3)^7 = 4374. a * (-2187) = 4374. a = -2.

AI explanation

Using the nth term of a geometric sequence formula t_n = a * r^(n-1), we plug in r = -3, n = 8, and t_8 = 4374 to get 4374 = a * (-3)^7. This simplifies to 4374 = a * (-2187), so a = 4374 / (-2187) = -2. The first term is -2.

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