#### Answer

$ x \geq 0$

#### Work Step by Step

You can not take the square root of a negative number. Therefore, $\frac{x}{3}$ must be greater than or equal to 0.
$ \frac{x}{3} \geq 0$
We multiply 3 to both sides
$ \frac{x}{3} \times 3 \geq 0 \times 3$
3 times 0 is 0
$ x \geq 0$