A =$\frac{2}{\sqrt[]{6}-2}$ +$\frac{2}{\sqrt[]{6}+2}$+$\frac{5}{\sqrt[]{6}}$
=$\frac{2.(\sqrt[]{6}+2)}{(\sqrt[]{6}-2).(\sqrt[]{6}+2)}$ +$\frac{2.(\sqrt[]{6}-2)}{(\sqrt[]{6}+2)(\sqrt[]{6}-2)}$+$\frac{5}{\sqrt[]{6}}$
=$\frac{2.\sqrt[]{6}+4+2.\sqrt[]{6}-4}{(\sqrt[]{6}-2).(\sqrt[]{6}+2)}$ +$\frac{5}{\sqrt[]{6}}$
=$\frac{4.\sqrt[]{6}}{6-4}$ +$\frac{5}{\sqrt[]{6}}$
=$\frac{4.\sqrt[]{6}}{2}$ +$\frac{5}{\sqrt[]{6}}$
=2$\sqrt[]{6}$ +$\frac{5}{\sqrt[]{6}}$
= $\frac{2.6}{ \sqrt[]{6}}$ +$\frac{5}{\sqrt[]{6}}$
=$\frac{17}{ \sqrt[]{6}}$
=$\frac{17\sqrt[]{6}}{ 6}$
Vậy A = $\frac{17\sqrt[]{6}}{ 6}$
