Question

Help?

Answer 1

9. What is the 10th term of the sequence 81, 27, 9, …
@timo86m

Answer 2

Can you tell what the relation between the terms is?

Answer 3

@Xavier its r=0.3333333333

Answer 4

Why the repeating decimal? But yeah it's geometric with r=1/3. You can keep up the pattern to find the 10th term or use the general formula for a geometric sequence

Answer 5

wait what?

Answer 6

is it 1/81

Answer 7

@Xavier

Answer 8

Write them all out and see if you have the 10th one

Answer 9

Im not sure how to do that

Answer 10

You have
81, 27, 9 so far. What is the next term?

Answer 11

@Xavier i continue to get 1/81 is that wrong...

Answer 12

use geometric sequence

Answer 13

http://en.wikipedia.org/wiki/Geometric_progression
81*r^1 = 27
^ first term
^ is a ratio you solve for
solving for r you get 1/3

now plug it back in
81*(1/3)^9=.0041152= 1/243
^ here we use 9 since the formula uses 0 for the first term and you want 10th.