Identify the Sequence 7/9 , -7/3 , 7 , -21 , 63

This is a geometric sequence since there is a common ratio between each term. In this case, multiplying the previous term in the sequence by ${\displaystyle -3}$ gives the next term. In other words, ${\displaystyle a_n=a_1{r}^{n-1}}$.

This is the form of a geometric sequence.

Substitute in the values of ${\displaystyle a_1=\frac{7}{9}}$ and ${\displaystyle r=-3}$.