You found the square root of some factors in the radicand instead of the cube root. Rewrite using $\displaystyle\frac{{{\sqrt[{{3}}]{{a}}}}}{{{\sqrt[{{3}}]{{b}}}}}={\sqrt[{{3}}]{{\frac{{a}}{{b}}}}}\usepackage{cmbright}\Huge\$ . Identify common factors in the numerator and denominator and simplify. Identify perfect cubes and pull them out of the radical. The correct answer is $\displaystyle{{y}}^{{2}}{\sqrt[{{3}}]{{{9}{y}}}}\usepackage{cmbright}\Huge\$ .