\(A=\sqrt[3]{3\sqrt{2}+7}-\sqrt[3]{3\sqrt{2}-7}\)
=>\(A^3=3\sqrt{2}+7-3\sqrt{2}+7-3\cdot A\cdot\sqrt[3]{18-49}\)
=>\(A^3=14-3\cdot A\cdot\sqrt[3]{-31}\)
=>\(A\simeq3,64\)
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