SOLUTION: find the 9th term og the geometric sequence -8/9, -8/3, -8

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Question 332434: find the 9th term og the geometric sequence
-8/9, -8/3, -8

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
-8/9, -8/3, -8

To find the common ratio r, we divide the 2nd term by the 1st term:

-8%2F3%22%F7%22-8%2F9%22%22=%22%22-8%2F3%22%22%2A%22%22-9%2F8%22%22=%22%223

And as a check we divide the 3rd term by the 2nd term to see if we get
the same common ratio:

-8%22%F7%22-8%2F3%22%22=%22%22-8%22%22%2A%22%22-3%2F8%22%22=%22%223

The formula for the nth term is:

a%5Bn%5D%22%22=%22%22a%5B1%5Dr%5E%28n-1%29

So substitute n=9, a%5B1%5D=-8%2F9 and r=3

a%5B9%5D%22%22=%22%22%28-8%2F9%29%283%29%5E%289-1%29

a%5B9%5D%22%22=%22%22%28-8%2F9%293%5E8

a%5B9%5D%22%22=%22%22-5832

Edwin