Question

-2, 12, -72...Find the common ratio of the geometric sequence.

Answer 1

ANSWER

$r=-6$

EXPLANATION

We want to find the common ratio of the geometric sequence.

$-2,12,-72$

To do this, divide a term by its preceeding term.

Let us divide 12 by -2 and -72 by 12:

That is:

$\begin{gathered} \Rightarrow r=\frac{12}{-2} \\ r=-6 \\ \Rightarrow r=\frac{-72}{12} \\ r=-6 \end{gathered}$

The common ratio is 6.