Rationalizing radical expressions 
$\sqrt [ 3 ]{\frac{3}{4}  }$  is the expression.
  What i did was change it to an equivalent fraction $({\sqrt [ 3 ]{\frac{6}{8}  }=\frac{\sqrt [ 3 ]{  6}}{2} } )$. But i think it isn't right.
  Please help me.  


If you did this,
you were correct
(writing out every possible step):
$$\sqrt[3]{\frac{3}{4}}
=\sqrt[3]{\frac{2\times 3}{2\times 4}}
=\sqrt[3]{\frac{6}{8}}
=\frac{\sqrt[3]{6}}{\sqrt[3]{8}}
=\frac{\sqrt[3]{6}}{2}
$$
