Which of the following is a geometric sequence?
Question 12 options:

A)

1, 5, 9, 13, 17, ...

B)

5, 1, –3, –7, –11, –15, ...

C)

2, 6, 18, 54, 162, 486, ...

D)

0, 5, 10, 15, 20, ...

Let's start by first remembering what a "geometric sequence" is. A geometric sequence is a sequence of numbers that multiply by the same number each time. For example,

2, 4, 8, 16

is a geometric sequence since each number is multiplied by 2 from one to the next, but

2, 4, 6, 8 

is NOT a geometric sequence. We are adding 2 each time, but not multiplying, so it doesn't count. We have to be multiplying to have a geometric sequence.

[A] Let's look at A, are we multiplying by the same thing? 

6*3 = 18

18*3 = 54

54*3 = 162

162*3 = 486

Yes! We are multiplying by 3 each time. This is a geometric sequence!

[B] Are we multiplying by the same thing?

2*3/2 = 3

3*3/2 = 9/2 which is not 5.

NOPE

[C] Are we multiplying by the same thing?

2*5/2 = 5

5*5/2 = 25/2 which is not 8

NOPE

[D] Are we multiplying by the same thing?

-4*1/2 = -2

-2*1/2 = -1

-1*1/2 = -0.5

-0.5*1/2 = -0.25

-0.25*1/2 = -0.125

Yep, we are multiplying by 1/2 each time! This is a geometric sequence!

hope this help im not sure tho

Step-by-step explanation:

-1/2 +2

step-by-step explanation:

step-by-step explanation: