Help meeee..................................

$\text{a) Vế trái = ($\dfrac{2\sqrt{3} - \sqrt{6}}{\sqrt{8} - 2}$ - $\dfrac{\sqrt{216}}{3}$) . $\dfrac{1}{\sqrt{6}}$ }$

$\text{= ($\dfrac{\sqrt{2} . \sqrt{2} . \sqrt{3} - \sqrt{6}}{\sqrt{4 . 2} - 2}$ - $\dfrac{\sqrt{36 . 6}}{3}$) . $\dfrac{1 . \sqrt{6}}{\sqrt{6} . \sqrt{6}}$ }$

$\text{= ($\dfrac{\sqrt{2} . \sqrt{6} - \sqrt{6}}{2\sqrt{2} - 2}$ - $\dfrac{6\sqrt{6}}{3}$) . $\dfrac{\sqrt{6}}{(\sqrt{6})²}$ }$

$\text{= [$\dfrac{\sqrt{6}(\sqrt{2} - 1)}{2(\sqrt{2} - 1)}$ - 2$\sqrt{6}$] . $\dfrac{\sqrt{6}}{6}$ }$ 

$\text{= ($\dfrac{\sqrt{6}}{2}$ - 2$\sqrt{6}$) . $\dfrac{\sqrt{6}}{6}$ }$

$\text{= $\dfrac{\sqrt{6} - 2\sqrt{6} . 2}{2}$  . $\dfrac{\sqrt{6}}{6}$ }$

$\text{= $\dfrac{\sqrt{6} - 4\sqrt{6}}{2}$ . $\dfrac{\sqrt{6}}{6}$ }$

$\text{= $\dfrac{-3\sqrt{6}}{2}$ . $\dfrac{\sqrt{6}}{6}$ }$

$\text{= $\dfrac{-3 . (\sqrt{6})² }{12}$ }$

$\text{= $\dfrac{-3 . 6}{12}$ }$

$\text{= $\dfrac{-3}{2}$ }$

$\text{= -1,5}$

$\text{= Vế phải}$

$\text{⇒ ($\dfrac{2\sqrt{3} - \sqrt{6}}{\sqrt{8} - 2}$ - $\dfrac{\sqrt{216}}{3}$) . $\dfrac{1}{\sqrt{6}}$ = -1,5}$

$\text{b) Vế trái = ($\dfrac{\sqrt{14} - \sqrt{7}}{1 - \sqrt{2}}$ + $\dfrac{\sqrt{15} - \sqrt{5}}{1 - \sqrt{3}}$) : $\dfrac{1}{\sqrt{7} - \sqrt{5}}$ }$

$\text{= [-$\dfrac{\sqrt{7}(\sqrt{2} - 1)}{\sqrt{2} - 1}$ - $\dfrac{\sqrt{5}(\sqrt{3} - 1)}{\sqrt{3} - 1}$] . ($\sqrt{7}$ - $\sqrt{5}$)}$

$\text{= (-$\sqrt{7}$ - $\sqrt{5}$)($\sqrt{7}$ - $\sqrt{5}$)}$

$\text{= -($\sqrt{7}$ + $\sqrt{5}$)($\sqrt{7}$ - $\sqrt{5}$) }$

$\text{= -[($\sqrt{7}$)² - ($\sqrt{5}$)²]}$

$\text{= -(7 - 5)}$

$\text{= -2}$

$\text{= Vế phải}$

$\text{⇒ ($\dfrac{\sqrt{14} - \sqrt{7}}{1 - \sqrt{2}}$ + $\dfrac{\sqrt{15} - \sqrt{5}}{1 - \sqrt{3}}$) : $\dfrac{1}{\sqrt{7} - \sqrt{5}}$ = -2}$

$\textit{Ha1zzz}$