Writing geometric series formula?

Question

This is my formula $t_n=8*\frac{3}{2}^{n-1} $ for this geometric series 8,12,18,27... My book has this formula for the same series: $t_n=\frac{16}{3}(\frac{3}{2})^n$. I tried both and they work, so how do I arrive at the form my book has presented? My book's equation doesn't follow the normal geometric series equation so I am a bit lost.

Answer 1

$8\cdot \frac{2}{3}\cdot \frac{3}{2}\cdot \left(\frac{3}{2}\right)^{n-1}=?$.

Notice $\frac{2}{3}\cdot \frac{3}{2}=1$ so I did not change the value.