# What is the nth term of the geometric sequence 5,15,45,135?

Apr 8, 2016

${a}_{n} = 3 {a}_{n - 1}$

#### Explanation:

Each time, the term is three times the last, which is written mathematically as

${a}_{n} = 3 {a}_{n - 1}$.

The $n$th term is the term before it multiplied by three.

$3$ is known as the common ratio.