We are asked to solve the equation $\sqrt{\frac{x-9}{3}} = 2$ for $x$.

1. Problem Description

We are asked to solve the equation $\sqrt{\frac{x-9}{3}} = 2$ for $x$.

2. Solution Steps

First, square both sides of the equation:

$(\sqrt{\frac{x-9}{3}})^2 = 2^2$

$\frac{x-9}{3} = 4$

Next, multiply both sides of the equation by 3:

$3 \cdot \frac{x-9}{3} = 3 \cdot 4$

$x-9 = 12$

Finally, add 9 to both sides of the equation:

$x-9+9 = 12+9$

$x = 21$

3. Final Answer

$x = 21$