2) 3 13/15 + 6 7/10 ;

2) $$3 \frac{13}{15} + 6 \frac{7}{10} = (3 + 6) + (\frac{13}{15} + \frac{7}{10}) = 9 + (\frac{13 \cdot 2}{15 \cdot 2} + \frac{7 \cdot 3}{10 \cdot 3}) = 9 + (\frac{26}{30} + \frac{21}{30}) = 9 + \frac{47}{30} = 9 + 1 \frac{17}{30} = 10 \frac{17}{30}$$

Ответ: $$10 \frac{17}{30}$$