I'm going to assume you mean [ [tex]5^\frac{2}{3}[/tex] ]
We can use the formula [ [tex]a^\frac{x}{n} =\sqrt[n]{a^x}[/tex] ] to convert to radical form.
[tex]5^\frac{2}{3} = \sqrt[3]{5^2}[/tex]
Therefore, the number in radical form is [tex]\sqrt[3]{5^2}[/tex]
Best of Luck!