#### Answer

The explicit formula is $a_{n}$=2 $\times$ (3$)^{n-1}$

#### Work Step by Step

You have to use the explicit formula The explicit formula is $a_{n}$=$a_{1}$ $\times$ (r$)^{n-1}$.
The starting value is 2 so it is $a_{1}$.
You have the sequence 2,6,18 so use the common ratio formula(r=$\frac{{a_{2}}}{{a_{1}}}$) r=$\frac{6}{2}$=3 and r=$\frac{18}{6}$=3.So the common ratio is 3.Substitute the value of a1 and r into the explicit formula:
The explicit formula is $a_{n}$=2 $\times$ (3$)^{n-1}$