$\frac{1}{11 - 2\sqrt{30}} - \frac{1}{11 + 2\sqrt{30}} = \frac{11 + 2\sqrt{30} - (11 - 2\sqrt{30})}{(11 - 2\sqrt{30})(11 + 2\sqrt{30})} = \frac{4\sqrt{30}}{121 - 4 * 30} = \frac{4\sqrt{30}}{121 - 120} = 4\sqrt{30}$

$\frac{5}{3 + 2\sqrt{2}} + \frac{5}{3 - 2\sqrt{2}} = 5(\frac{1}{3 + 2\sqrt{2}} + \frac{1}{3 - 2\sqrt{2}}) = 5(\frac{3 - 2\sqrt{2} + 3 + 2\sqrt{2}}{(3 + 2\sqrt{2})(3 - 2\sqrt{2})}) = \frac{5 * 6}{9 - 4 * 2} = \frac{30}{9 - 8} = 30$

$\frac{\sqrt{5} - \sqrt{3}}{\sqrt{5} + \sqrt{3}} + \frac{\sqrt{5} + \sqrt{3}}{\sqrt{5} - \sqrt{3}} = \frac{(\sqrt{5} -\sqrt{3})^2 + (\sqrt{5} + \sqrt{3})^2}{(\sqrt{5} + \sqrt{3})(\sqrt{5} - \sqrt{3})} = \frac{5 - 2\sqrt{15} + 3 + 5 + 2\sqrt{15} + 3}{5 - 3} = \frac{16}{2} = 8$

$\frac{11 + \sqrt{21}}{11 - \sqrt{21}} + \frac{11 - \sqrt{21}}{11 + \sqrt{21}} = \frac{(11 + \sqrt{21})^2 + (11 - \sqrt{21})^2}{(11 - \sqrt{21})(11 + \sqrt{21})} = \frac{121 + 22\sqrt{21} + 21 + 121 - 22\sqrt{21} + 21}{121 - 21} = \frac{284}{100} = 2,84$