1) $$7\sqrt{6} - 2\sqrt{54} + \sqrt{96} = 7\sqrt{6} - 2\sqrt{9 \cdot 6} + \sqrt{16 \cdot 6} = 7\sqrt{6} - 2 \cdot 3\sqrt{6} + 4\sqrt{6} = 7\sqrt{6} - 6\sqrt{6} + 4\sqrt{6} = (7 - 6 + 4)\sqrt{6} = 5\sqrt{6}$$
Ответ: $$5\sqrt{6}$$
2) $$(\sqrt{80} - \sqrt{20})\sqrt{5} = (\sqrt{16 \cdot 5} - \sqrt{4 \cdot 5})\sqrt{5} = (4\sqrt{5} - 2\sqrt{5})\sqrt{5} = 2\sqrt{5} \cdot \sqrt{5} = 2 \cdot 5 = 10$$
Ответ: 10
3) $$(\sqrt{10} - 1)^2 = (\sqrt{10})^2 - 2 \cdot \sqrt{10} \cdot 1 + 1^2 = 10 - 2\sqrt{10} + 1 = 11 - 2\sqrt{10}$$
Ответ: $$11 - 2\sqrt{10}$$
4) $$(6\sqrt{3} + \sqrt{2})(6\sqrt{3} - \sqrt{2}) = (6\sqrt{3})^2 - (\sqrt{2})^2 = 36 \cdot 3 - 2 = 108 - 2 = 106$$
Ответ: 106