Answer
$\dfrac{-4}{729}$ or, $-0.00549$
Work Step by Step
The general formula to find the nth term of a Geometric sequence is given as: $ a_{n}=a_1r^{n-1}$
Here, $ a_1=12$ and $ r=\dfrac{-1}{3}$
Plug $ n=8$
$ a_{8}=12 \times (\dfrac{-1}{3})^{8-1}=12 \times (\dfrac{-1}{3})^{7}=\dfrac{-4}{729}=-0.00549$
