Answer
The next three terms are $5,-2.5,1.25$.
The graph is shown below.
Work Step by Step
The given sequence is
$80,-40,20,-10,...$
Use table to organize the terms.
Each term is divided by $-2$ to the previous term. So, the common ratio is $-\frac{1}{2}$.
Divide a term by $-2$ to find the next term.
Plot the ordered pairs $(n,a_n)$.
The complete table is shown below.
