Освободимся от иррациональности в знаменателе:
- $$\frac{8}{3\sqrt{2}} = \frac{8\sqrt{2}}{3\sqrt{2} \cdot \sqrt{2}} = \frac{8\sqrt{2}}{3 \cdot 2} = \frac{4\sqrt{2}}{3}$$
- $$\frac{4}{\sqrt{13} - 3} = \frac{4(\sqrt{13} + 3)}{(\sqrt{13} - 3)(\sqrt{13} + 3)} = \frac{4(\sqrt{13} + 3)}{13 - 9} = \frac{4(\sqrt{13} + 3)}{4} = \sqrt{13} + 3$$
Ответ: 1) $$\frac{4\sqrt{2}}{3}$$, 2) $$\sqrt{13} + 3$$