A) \(\frac{1}{5+3\sqrt{2}} + \frac{1}{5-3\sqrt{2}};\) b) \(\frac{1}{\sqrt{5}+1} + \frac{1}{\sqrt{5}-2} - \frac{1}{3-\sqrt{5}} - \sqrt{5}.\) c) \(\sqrt{\frac{3}{20}} + \sqrt{\frac{1}{60}} - 2\sqrt{\frac{1}{15}}.\)