7 9 16—+6—= 15 15 8 15 5—+14—= 29 29 9 23 5 9—+3—= 27 27

Выполним сложение дробей:

1. $$16 \frac{9}{15} + 6 \frac{9}{15} = (16+6) + (\frac{9}{15} + \frac{9}{15}) = 22 + \frac{9+9}{15} = 22 + \frac{18}{15} = 22 + 1\frac{3}{15} = 23\frac{3}{15}$$
2. $$5 \frac{15}{29} + 14 \frac{17}{29} = (5+14) + (\frac{15}{29} + \frac{17}{29}) = 19 + \frac{15+17}{29} = 19 + \frac{32}{29} = 19 + 1\frac{3}{29} = 20\frac{3}{29}$$
3. $$9 \frac{23}{27} + 3 \frac{5}{27} = (9+3) + (\frac{23}{27} + \frac{5}{27}) = 12 + \frac{23+5}{27} = 12 + \frac{28}{27} = 12 + 1\frac{1}{27} = 13\frac{1}{27}$$

Ответ: 1) $$23\frac{3}{15}$$, 2) $$20\frac{3}{29}$$, 3) $$13\frac{1}{27}$$