Missing terms of a geometric seqeunce

[EricPowell]

Homework Statement

Write the first 5 terms of the geometric sequence
3, __ , 3^2x+1, __, __

Homework Equations

t_n=ar^n-1

The Attempt at a Solution

t_n=ar^n-1
3^2x+1=3r^3-1
r²=3^2x+1 / 3
r=√3^2x+1 / √3

I'm stuck

 

[Villyer]

Before taking the square root, try to simplyfy the right side. What is \frac{3^{2x+1}}{3^{1}}?

 

[professordad]

Hint:

If a,b,c are three consecutive terms of a geometric sequence, b^2 = ac.

 

[EricPowell]

Before taking the square root, try to simplyfy the right side. What is \frac{3^{2x+1}}{3^{1}}?

Ohh I see. 3^2x+1 / 3¹ = 3^2x. And the square root of that is 3^x.
Thank you