The formula for any geometric sequence is an = a1 · rn - 1, where an represents the value of the nth term, a1 represents the value of the first term, r represents the common ratio, and n represents the term number. What is the formula for the sequence 2, -6, 18, -54, ...? an = 2 · 3n - 1 an = 2 · (-3)n - 1 an = 3 · 2n - 1 an = -3 · 2n - 1

The second choice

Step-by-step explanation:

So first we would plug in the first term which is 2 so we would get times so next we would see that the common ration is -3 since every time the number is being multiplied by -3. so then our equation would be times . Now we would just find the choice that matches and it would be the second choice.

option 2

Step-by-step explanation:

First term

common ratio = r = second term ÷ first term

                            = -6 ÷2 = -4

Plug in the values of   & r in the formula

first one because it can't have a fraction in it

step-by-step explanation:

hi there!

first we need to find out how much they are adding to each number to make the next number.

ex: 4 + 4 = 8, 8 + 8 = 16, and so on.

so continuing with 32,

32 + 32 = 64

64 + 64 = 128

128 + 128 = 256

256 + 256 = 512

4, 8, 16, 32, 64, 128, 256, 512

the 8th term of the sequence will be 512

hope this ! ~