Chapter 11 - Further Topics in Algebra - Chapter 11 Test Prep - Review Exercises - Page 1082: 18

$${a_5} = - 162$$

$$\eqalign{ & {a_1} = - 2,\,\,r = 3 \cr & {\text{The general term is }} \cr & {a_n} = {a_1}{r^{n - 1}} \cr & {a_n} = \left( { - 2} \right){\left( 3 \right)^{n - 1}} \cr & {\text{Calculate }}{a_5} \cr & {a_5} = \left( { - 2} \right){\left( 3 \right)^{5 - 1}} \cr & {a_5} = - 162 \cr} $$