2. Заполните пропуски: a) 2\(\frac{2}{5}\) + 7\(\frac{3}{10}\) = 9 + \(\frac{4}{10}\) + \(\frac{3}{10}\) = 9 \(\frac{7}{10}\) б) 6\(\frac{7}{8}\) + 3\(\frac{5}{12}\) = 9 + \(\frac{21}{24}\) + \(\frac{10}{24}\) = 9 + \(\frac{31}{24}\) = 10 \(\frac{7}{24}\)

Решение:

1. а) \( 2\frac{2}{5} + 7\frac{3}{10} = (2+7) + (\frac{2}{5} + \frac{3}{10}) = 9 + (\frac{4}{10} + \frac{3}{10}) = 9 + \frac{7}{10} = 9\frac{7}{10} \)


2. б) \( 6\frac{7}{8} + 3\frac{5}{12} = (6+3) + (\frac{7}{8} + \frac{5}{12}) = 9 + (\frac{21}{24} + \frac{10}{24}) = 9 + \frac{31}{24} \). Так как \(\frac{31}{24}\) — неправильная дробь, выделим целую часть: \( \frac{31}{24} = 1\frac{7}{24} \). Тогда \( 9 + 1\frac{7}{24} = 10\frac{7}{24} \)

Ответ: а) \( 2\frac{2}{5} + 7\frac{3}{10} = \boxed{9} + \frac{\boxed{4}}{10} + \frac{\boxed{3}}{10} = 9 \frac{7}{10} \); б) \( 6\frac{7}{8} + 3\frac{5}{12} = \boxed{9} + \frac{\boxed{21}}{24} + \frac{\boxed{10}}{24} = 9 + \frac{\boxed{31}}{24} = \boxed{10} \frac{7}{24} \).