Question

what is the pattern of -5,10,-20 and whats the rule?​

Answer 1

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

Answer 2

Answer:

multiply by -2

Step-by-step explanation:

x(-2)