Question

What is the common ratio for the following geometric sequence? 9, 18, 36, 72, 144
does that mean greatest commmon factor

Answer 1

no a geometric sequence is a sequence where each term is the previous term times a common ratio.

so:
18 = 9x
36 = 18x
72 = 36x
... and so on

what is x?

Answer 2

i do not get it

Answer 3

do you know what a sequence is?

Answer 4

yes but how do i know wht the common ratio is?

Answer 5

choose a term, look at the previous term, and determine what needs to be multiplied with the first term to achieve the second term.

in my equations above, you can solve for x and get the answer.

Answer 6

23 is common raito
????????

Answer 7

\[r = \frac{a_{n+1}}{a_n}\]

Answer 8

is the ratio 1:2? Because every term is twice the one before it?

Answer 9

how do i go about using that formula with what i am givin

Answer 10

\[r = \frac{a_{n+1}}{a_n} = \frac{a_2}{a_1} = \frac{18}{9} = 2\]

Answer 11

i though you do + 1 to a2 on top

Answer 12

I think you should first understand what a sequence is.

Answer 13

i do

Answer 14

The numbers below a are what are known as subscripts.

Answer 15

do u not add 1 to top?

Answer 16

They represent the index of the term in the sequence.

Answer 17

Geometric sequences have a common ratio which holds for any two given terms.

The formula for the ratio expresses this fact.

Answer 18

\(a_1 =\) the 1st term of the sequence
\(a_2 =\) the 2nd term of the sequence
\(a_3 =\) the 3rd term of the sequence
\(a_n =\) the nth term of the sequence
\(a_{n+1} =\) the (n + 1)th term of the sequence

so for any nth term, the nth plus 1 term is a multiple by what factor?

Answer 19

help me with my other question