Explicação passo a passo:
[tex]9x^3-3=0\\ \\ 9x^3=3\\ \\ x^3={3\over9}\\ \\ x^3={1\over3}\\ \\ x=\sqrt[3]{{1\over3}} \\ \\ x={\sqrt[3]{1} \over\sqrt[3]{3} }\\ \\ x={1\over\sqrt[3]{3}[/tex]
racionalizando
[tex]x={1\sqrt[3]{3^2} \over\sqrt[3]{3} .\sqrt[3]{3^2} }={\sqrt[3]{9} \over\sqrt[3]{3^3} }={\sqrt[3]{9} \over3}\\[/tex]
[tex]\fbox{$x={\sqrt[3]{9} \over3}$}[/tex]
