tính:a,\(\dfrac{5.\left(38^2-17^2\right)}{8.\left(47^2-19^2\right)}\)
b, \(\sqrt{\dfrac{0,2.1,21.0,3}{7,5.3,2.0,64}}\)
c, \(\sqrt{3+\sqrt{5}}-\sqrt{3-\sqrt{5}}-\sqrt{2}\)
d, \(\sqrt{4-\sqrt{7}}-\sqrt{4+\sqrt{7}}+\sqrt{7}\)
e, \(\sqrt{6,5+\sqrt{12}}+\sqrt{6,5-\sqrt{12}}+2\sqrt{6}\)