Consider a geometric sequence

let

and the common ratio be r, then the sequence is constructed as follows:

we can observe that each term of the sequence is its previous term * r.
In the given sequence, to find the common ratio we divide 6,561 by −2,187 and get -3. This means that

Let the first term

,
then the eighth term is

Answer: -3
X=9
You would do 54 divided by 5x and it would equal to 9 that means x is 9
Simplify the fraction and you should get a bunch of multiplex linear equations with solving for y multi step problems of the fraction
The answer would be B because the average rate of change formula calculates slope of lines, or a curve on a given range.it is defines as the ratio of the difference in the function (f/x) as it changes from "a" to "b" and the difference between "a" and "b" so ya answer is B
hope this helps, ~kashout