Question

What's the 6th term in a sequence that starts with -7.5 and has a common ratio of 9?

Answer 1

$\bf n^{th}\textit{ term of a geometric sequence}\\\\ a_n=a_1\cdot r^{n-1}\qquad \begin{cases} n=n^{th}\ term\\ a_1=\textit{first term's value}\\ r=\textit{common ratio}\\ ----------\\ a_1=-7.5\\ r=9\\ n=6 \end{cases}\implies a_6=-7.5\cdot 9^{6-1}$