Question

Find the given term 11, -33,99 9th term

Answer 1

Assuming the sequence goes on like this 11,-33,99,-297,891,...,
its general formula is $a_n=-11\cdot(-1)^n\cdot3^{n-1}$

So, the 9th term is
$a_9=-11\cdot(-1)^9\cdot3^{9-1}=-11\cdot(-1)\cdot6561=72171$