Tính
A= \(\sqrt{4+\sqrt{15}}\)- \(\sqrt{4-\sqrt{15}}\) -\(\sqrt{2-\sqrt{3}}\)
B= \(\sqrt{9-2\sqrt{14}}\) +\(\sqrt{9-2\sqrt{14}}\)
C= \(\left(4+\sqrt{15}\right)\) \(\left(\sqrt{10}-\sqrt{6}\right)\) \(\sqrt{4-\sqrt{15}}\)
D= \(\dfrac{2+\sqrt{3}}{\sqrt{2}+\sqrt{2}+\sqrt{3}}\) + \(\dfrac{2-\sqrt{3}}{\sqrt{2}-\sqrt{2\sqrt{3}}}\)