## Intermediate Algebra (6th Edition)

$a_{9}=1,280$
Using $a_n=a_1r^{n-1}$ or the $n$th term of a geometric sequence, then, \begin{array}{l} a_{9}=5(2)^{9-1} \\ a_{9}=5(256) \\ a_{9}=1,280 .\end{array}