Answer
$80$
Work Step by Step
We know that in a geometric sequence, if $a_1$ is the first term and $r$ is the common ratio, then the $n^{th}$ term is given by he fomumla $a_n=a_1\cdot r^{n-1}.$
Hence, here
$a_n=5\cdot (-2)^{n-1}$
Thus,
$a_{5}=5\cdot (-2)^{5-1}=80$
