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I need to find the 9th term of this sequence

I need to find the 9th term of this sequence-example-1

1 Answer

13 votes

9514 1404 393

Answer:

26,244

Explanation:

The sequence is geometric with a common ratio of -3. The general term is ...

an = (a1)r^(n-1)

The first term is 4, so we have ...

an = 4·(-3)^(n-1)

For n=9, we find the 9th term to be ...

a9 = 4·(-3)^(9-1) = 4·3^8

a9 = 26,244

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Additional comment

When -3 is raised to an even power, the sign of the product is positive, the same as 3 raised to that power.

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