Answer :
[tex]\bf -5~~,~~\stackrel{-5(-2)}{10}~~,~~\stackrel{10(-2)}{20}\quad \qquad a_n=a_{n-1}(-2)~~ \begin{cases} n=\textit{term position}\\ n-1=\textit{position before it} \end{cases}[/tex]
[tex]\bf -5~~,~~\stackrel{-5(-2)}{10}~~,~~\stackrel{10(-2)}{20}\quad \qquad a_n=a_{n-1}(-2)~~ \begin{cases} n=\textit{term position}\\ n-1=\textit{position before it} \end{cases}[/tex]
