(√2/3 + √3/2) x √6

$$\begin{gathered} bai6 =\left(\sqrt{\frac{2}{3}}+\sqrt{\frac{3}{2}}\right)\times \sqrt{6} \\ bai7 =\left(1-\sqrt{2}\right)\times \frac{2+\sqrt{2}}{\sqrt{2}} \\ bai8 =\frac{\sqrt{2}-\sqrt{6}}{1-\sqrt{3}}\frac{2-\sqrt{8}}{1-\sqrt{2}} \\ bai9 =\frac{\sqrt{3}+\sqrt{15}}{1+\sqrt{5}}\frac{3-\sqrt{27}}{1-\sqrt{3}} \\ giup e dc ko a \end{gathered}$$