precalculus math help

Question

find the common ratio for the following series

Answer 1

It's helpful to make a table of the series by plugging in values of x into the expression and evaluating:

x f(x)

-3 -3645

-2 -405

-1 -45

0 -5

1 -0.555..

.... .....

Now, take the ratio of the first value and the second...

-3645 / -405 = 9

And the second to the third...

-405 / -45 = 9

And the third to the fourth....

-45 / -5 = 9

So 9 is the common ratio.