Question

Need help on this one plizz

Answer 1

`\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's value}\\ r=\textit{common ratio}\\ ----------\\ n=9\\ a_1=1\\ r=-(1)/(3) \end{cases}\implies a_9=1\left( -(1)/(3) \right)^(9-1)`