$$ \left(\frac{1 + \,i \,\sqrt{ 3} }{1 -\,i \, \sqrt{3}}\right)^7 $$
konjugiert komplex erweitern
$$ \left(\frac{1 + \,i \,\sqrt{ 3} }{1 -\,i \, \sqrt{3}}\cdot\frac{1 + \,i \,\sqrt{ 3} }{1 +\,i \, \sqrt{3}}\right)^7 $$
3. binomische Formel anwenden
$$ \left(\frac{(1 + \,i \,\sqrt{ 3} )^2}{1 + \, {3}}\right)^7 $$