a) $$ \frac{8}{3\sqrt{2}} = \frac{8\sqrt{2}}{3\sqrt{2} \cdot \sqrt{2}} = \frac{8\sqrt{2}}{3 \cdot 2} = \frac{8\sqrt{2}}{6} = \frac{4\sqrt{2}}{3}$$.
б) $$ \frac{10}{\sqrt{14}-2} = \frac{10(\sqrt{14}+2)}{(\sqrt{14}-2)(\sqrt{14}+2)} = \frac{10(\sqrt{14}+2)}{14-4} = \frac{10(\sqrt{14}+2)}{10} = \sqrt{14}+2$$.
Ответ: а) $$ \frac{4\sqrt{2}}{3}$$; б) $$\sqrt{14}+2$$