[tex]\bf n^{th}\textit{ term of a geometric sequence}\\\\
a_n=a_1\cdot r^{n-1}\qquad
\begin{cases}
n=n^{th}\ term\\
a_1=\textit{first term}\\
r=\textit{common ratio}\\
--------\\
a_1=5\\
r=-\frac{1}{2}\\
n=6
\end{cases}\implies a_6=(5)\left( -\frac{1}{2} \right)^{6-1}
\\\\\\
a_6=(5)\left( -\frac{1}{2} \right)^{5}\implies a_6=(5)\frac{(-1)^5}{2^5}\implies a_6=\cfrac{-5}{32}[/tex]