Solve the equation 3/√2x

To simplify a rational expression with a root in the denominator, we need to multiply the numerator and denominator by the root.
To simplify ${\displaystyle \frac{3}{\sqrt{2x}}}$, we then need to multiply the numerator and denominator by ${\displaystyle \sqrt{2}x}$, which gives ${\displaystyle \frac{\frac{(3\times \sqrt{2}x)}{\left(\sqrt{2}x\right)\left(\sqrt{2}x\right)}}{}}$.
Using the property ${\displaystyle \sqrt{x}\times \sqrt{x}=x}$ where $x>0$ to simplify the denominator then gives $\frac{3}{(\sqrt{2x})(\sqrt{2x})}=\frac{3}{\sqrt{\frac{2x}{2x}}}$