Question

What is the common ratio of the sequence?
-2,6,-18,54

Answer 1

The common ratio is -3.

Step-by-step explanation

In general, the common ratio of a Geometric Sequence is given by:

`r = (a_(n+1))/(a_(n))`

We can find the common ratio using any two consecutive terms of the geometric sequence by dividing the subsequent term by the previous term.

The given sequence is -2,6,-18,54

Using the first two terms the common ratio is

`r = (6)/( - 2) = - 3`

We could also used the second and third terms to get

`r = ( - 18)/(6) = - 3`

and so on and so forth.

Therefore the common ratio is -3.