## Precalculus (6th Edition) Blitzer

$\dfrac{-4}{729}$ or, $-0.00549$
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 $n=8$ $a_{8}=12 \times (\dfrac{-1}{3})^{8-1}=12 \times (\dfrac{-1}{3})^{7}=\dfrac{-4}{729}=-0.00549$