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13 votes
13 votes
{-2, 6, -18, 54.-162,...}
Can anyone please find the explicit rule and 10th term please.

User Prabin Badyakar
by
2.1k points

2 Answers

28 votes
28 votes

Answer:

see explanation

Explanation:

There is a common ratio between consecutive terms , that is

6 ÷ - 2 = - 18 ÷ 6 = 54 ÷ - 18 = - 162 ÷ 54 = - 3

This indicates the sequence is geometric with explicit rule


a_(n) = a₁
(r)^(n-1)

where a₁ is the first term and r the common ratio

Here a₁ = - 2 and r = - 3 , then

a₁₀ = - 2
(-3)^(9) = - 2 × - 19683 = 39366

User Trelzevir
by
3.0k points
21 votes
21 votes

10th number is: 39366

Example of sequence:

(common ratio is found by [6/-2], [-18/6] which both give -3)

{-2, 6, -18, 54.-162,...} Can anyone please find the explicit rule and 10th term please-example-1
User Ben Dyer
by
3.2k points