3．
计算：
\((1)\sqrt{6}\times \sqrt{\dfrac{2}{3}}\)
\((2)2\sqrt{12}+\sqrt{48}\)
\((3) \dfrac{1}{4} \sqrt{8}÷2 \sqrt{ \dfrac{1}{2}}×\left(-2 \sqrt{2}\right) \)
\((4)4{{\left( \sqrt{3}+\sqrt{7} \right)}^{0}}+\sqrt{\dfrac{1}{2}}\times \sqrt{8}-{{\left( 1-\sqrt{2} \right)}^{2}}\)
\((5)\left( 7+4\sqrt{3} \right){{\left( 2-\sqrt{3} \right)}^{2}}\)
\((6)\dfrac{\sqrt{3}}{3+\sqrt{3}}+\sqrt{12}-{{\left( \sqrt{3}+1 \right)}^{2}}+\sqrt{\dfrac{3}{4}}\)