Решение:
1. a) \( \frac{4}{5} \sqrt{75} + \sqrt{2(\sqrt{8} - \sqrt{24})} \):
- \( \frac{4}{5} \sqrt{75} = \frac{4}{5} \cdot 5 \sqrt{3} = 4 \sqrt{3} \).
- \( \sqrt{8} - \sqrt{24} = 2\sqrt{2} - 2\sqrt{6} \), \( \sqrt{2(\sqrt{8} - \sqrt{24})} = \sqrt{2 \cdot 2\sqrt{2} - 2 \cdot 2\sqrt{6}} = \sqrt{4\sqrt{2} - 4\sqrt{6}} \).
- Итог: \( 4\sqrt{3} + \sqrt{4\sqrt{2} - 4\sqrt{6}} \).
2. b) \( (\sqrt{8} - \sqrt{5})^2 \):
- \( (\sqrt{8} - \sqrt{5})^2 = 8 + 5 - 2 \sqrt{8} \sqrt{5} = 13 - 2 \sqrt{40} = 13 - 4\sqrt{10} \).
- Итог: \( 13 - 4\sqrt{10} \).