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Решите задачу:

$\sqrt{8-\sqrt{28}}- \sqrt{8+\sqrt{28}} =\sqrt{8-\sqrt{4*7}}- \sqrt{8+\sqrt{4*7}} =\\=\sqrt{8-2\sqrt{7}}- \sqrt{8+2\sqrt{7}} =\sqrt{1+7-2\sqrt{7}}- \sqrt{1+7+2\sqrt{7}}=\\=\sqrt{\sqrt1^2+\sqrt7^2-2\sqrt{7}*\sqrt1}- \sqrt{\sqrt1^2+\sqrt7^27+2\sqrt{7}*\sqrt1}=\\=\sqrt{(\sqrt1-\sqrt7)^2}- \sqrt{(\sqrt1+\sqrt7)^2}=\sqrt7-\sqrt1-(\sqrt1+\sqrt7)=\\=\sqrt7-\sqrt1-\sqrt1-\sqrt7=2\sqrt1=2*1=2\\ \\$

$\sqrt{6+4\sqrt{2}}- \sqrt{6-4\sqrt{2}} =\sqrt{4+2+2*2\sqrt{2}}- \sqrt{4+2-2*2\sqrt{2}} =\\=\sqrt{2^2+\sqrt2^2+2*2\sqrt{2}}- \sqrt{2^2+\sqrt2^2-2*2\sqrt{2}} =\\=\sqrt{(2+\sqrt2)^2}- \sqrt{(2-\sqrt2)^2} =2+\sqrt2-(2-\sqrt2)=\\=2+\sqrt2-2+\sqrt2=2\sqrt2\\$