Review question

# If $S_n = 6 - 2^{n+1}/3^{n-1}$, can we show that we have a GP? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R8163

## Question

The sum of the first $n$ terms of a series is given by the expression $\begin{equation*} 6 - \frac{2^{n+1}}{3^{n-1}}. \end{equation*}$

By finding an expression for the $n$th term of the series, or otherwise, show that this is a geometric series, and state the values of the first term and the common ratio.