[tex](\frac{2}{\sqrt{5}}-\frac{11\sqrt{5}}{5})*(\frac{\sqrt{5}}{5}-\frac{4}{\sqrt{5}})^{-1}=\\ \\ (\frac{2\sqrt{5}-11\sqrt{5}}{5})*(\frac{\sqrt{5}-4\sqrt{5}}{5})^{-1}=\\ \\ \frac{-9\sqrt{5}}{5} *(\frac{-3\sqrt{5}}{5})^{-1}=\\ \\ \frac{-9\sqrt{5}}{5}*\frac{1}{\frac{-3\sqrt{5}}{5}}=3.[/tex]
@robertinnifd
