\frac{2}{\sqrt5-2}
\frac{5-\sqrt3}{1+\sqrt3}
\frac{2}{\sqrt5-2}=\frac{2}{\sqrt5-2} * \frac{\sqrt5+2}{\sqrt5+2}=\frac{2(\sqrt5+2}{5-4}=2(\sqrt5+2)
\frac{5-\sqrt3}{1+\sqrt3}=\frac{5-\sqrt3}{1+\sqrt3} * \frac{1-\sqrt3}{1-\sqrt3}=\frac{5-5\sqrt3-\sqrt3+3}{1-3}=\frac{8-6\sqrt3}{-2}=-4+3\sqrt3