10) 13 4/9:

10) $$ \sqrt{13\frac{4}{9}} = \sqrt{\frac{13 \cdot 9 + 4}{9}} = \sqrt{\frac{117 + 4}{9}} = \sqrt{\frac{121}{9}} = \frac{\sqrt{121}}{\sqrt{9}} = \frac{11}{3} = 3\frac{2}{3}$$

Ответ: 11/3