assuming yo meant
[tex]x^3= \frac{64}{27} [/tex]
reemmeber
[tex] \sqrt{ \frac{x}{y} } = \frac{ \sqrt{x} }{ \sqrt{y} } [/tex]
so
[tex]x^3= \frac{64}{27} [/tex]
cube root both sides
[tex]x= \sqrt[3]{ \frac{64}{27}} [/tex]
[tex]x= \frac{ \sqrt[3]{64} }{ \sqrt[3]{27} } [/tex]
[tex]x= \frac{4}{3} [/tex]
