4. Упростить выражение:
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$$(1+\sqrt{5})^2 = 1 + 2\sqrt{5} + 5 = 6 + 2\sqrt{5}$$
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$$(\sqrt{5}-\sqrt{3})(\sqrt{5}+\sqrt{3}) = 5 - 3 = 2$$
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$$(3\sqrt{14}+\sqrt{7})\sqrt{7} - 2\sqrt{2} = 3\sqrt{14}\sqrt{7} + 7 - 2\sqrt{2} = 3\sqrt{2}\sqrt{7}\sqrt{7} + 7 - 2\sqrt{2} = 21\sqrt{2} + 7 - 2\sqrt{2} = 19\sqrt{2} + 7$$
Ответ: 1) $$6 + 2\sqrt{5}$$; 2) 2; 3) $$19\sqrt{2} + 7$$