The rule for rewriting rational exponents is: $\displaystyle{{x}}^{{\frac{{m}}{{n}}}}={\sqrt[{{n}}]{{{{x}}^{{m}}}}}\usepackage{cmbright}\Huge\$

The denominator of the fraction is 5, so this denominator becomes a fifth root. Because there are no parentheses, the exponent refers only to the quantity immediately to its left.

$\displaystyle{6}{{x}}^{{\frac{{3}}{{5}}}}={6}\cdot{{x}}^{{\frac{{3}}{{5}}}}={6}{\sqrt[{{5}}]{{{{x}}^{{3}}}}}\usepackage{cmbright}\Huge\$