10.7. a) $$\sqrt{\frac{4}{9}}$$; б) $$\sqrt{\frac{36}{49}}$$; г) $$\sqrt{\frac{16}{121}}$$.

a) $$\sqrt{\frac{4}{9}} = \frac{\sqrt{4}}{\sqrt{9}} = \frac{2}{3}$$

б) $$\sqrt{\frac{36}{49}} = \frac{\sqrt{36}}{\sqrt{49}} = \frac{6}{7}$$

г) $$\sqrt{\frac{16}{121}} = \frac{\sqrt{16}}{\sqrt{121}} = \frac{4}{11}$$