$\dfrac {\sqrt {5}-\dfrac {1} {\sqrt {5}}} {\sqrt {5}+\dfrac {1} {\sqrt {5}}}:\sqrt {\dfrac {2} {3}}$
$\frac{\frac{4}{\sqrt{5}}}{\frac{6}{\sqrt{5}}}$.$\sqrt{\frac{3}{2}}$=$\sqrt{\frac{2}{3}}$