Calcolare le seguenti potenze con base razionale ed esponente intero.

$\displaystyle \left( +\frac{2}{3}\right)^{0}= +1$
$\displaystyle \left( -\frac{2}{3}\right)^{0}= +1$
$\displaystyle \left( +\frac{2}{3}\right)^{1}= +\frac{2}{3}$
$\displaystyle \left( -\frac{2}{3}\right)^{1}= -\frac{2}{3}$
$\displaystyle \left( +\frac{2}{3}\right)^{2}= +\frac{4}{9}$
$\displaystyle \left( -\frac{2}{3}\right)^{2}=+\frac{4}{9}$
$\displaystyle \left( +\frac{2}{3}\right)^3=+\frac{8}{27}$
$\displaystyle \left( -\frac{2}{3}\right)^3=-\frac{8}{27}$
$\displaystyle \left( -\frac{2}{3}\right)^{-2} =\left( -\frac{3}{2}\right)^{2}=+\frac{9}{4} $
$\displaystyle \left( -\frac{2}{3}\right)^{-3} =\left( -\frac{3}{2}\right)^{3}=-\frac{27}{8} $