15) \( \frac{3 + 2\sqrt{3}}{\sqrt{3}} + \frac{2 + \sqrt{2}}{\sqrt{2 + 1}} - \left( \sqrt{2 + \sqrt{3}} \right); \) 16) \( \frac{\sqrt{15} - \sqrt{5}}{\sqrt{3} - 1} \cdot \frac{1}{\sqrt{5} - 2} + \sqrt{9 + 4\sqrt{5}} \)