C) \( 5\sqrt{2a} - \sqrt{50a} - 2\sqrt{a^3} + 4\sqrt{32a} \) với \( a \geq 0 \) d) \( A = \frac{5 + \sqrt{5}}{\sqrt{5} + 2} + \frac{5}{\sqrt{5} - 1} - \frac{3\sqrt{5}}{3 + \sqrt{5}} \) e) \( B = 21\left(\sqrt{2} + \sqrt{3} + \sqrt{3} - \sqrt{5}\right)^2 - 6\left(\sqrt{2} - \sqrt{3} + \sqrt{3} + \sqrt{5}\right)^2 - 15\sqrt{15}. \)

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c) \( 5\sqrt{2a} - \sqrt{50a} - 2\sqrt{a^3} + 4\sqrt{32a} \) với \( a \geq 0 \)

d) \( A = \frac{5 + \sqrt{5}}{\sqrt{5} + 2} + \frac{5}{\sqrt{5} - 1} - \frac{3\sqrt{5}}{3 + \sqrt{5}} \)

e) \( B = 21\left(\sqrt{2} + \sqrt{3} + \sqrt{3} - \sqrt{5}\right)^2 - 6\left(\sqrt{2} - \sqrt{3} + \sqrt{3} + \sqrt{5}\right)^2 - 15\sqrt{15}. \)