2. Выполните действия: 9\frac{5}{21}-(10\frac{2}{3}-3\frac{5}{28});6\frac{13}{15}+3\frac{7}{12}-4\frac{9}{20}

1) 10\frac{2}{3}-3\frac{5}{28} = 10\frac{56}{84} - 3\frac{15}{84} = 7\frac{41}{84}

2) 9\frac{5}{21} - 7\frac{41}{84} = 9\frac{20}{84} - 7\frac{41}{84} = 8\frac{104}{84} - 7\frac{41}{84} = 1\frac{63}{84} = 1\frac{3}{4}

3) 6\frac{13}{15}+3\frac{7}{12}-4\frac{9}{20} = 6\frac{52}{60} + 3\frac{35}{60} - 4\frac{27}{60} = 9\frac{87}{60} - 4\frac{27}{60} = 5\frac{60}{60} = 6

4) 1\frac{3}{4} ; 6 = \frac{7}{4} \cdot \frac{1}{6} = \frac{7}{24}

Ответ: \frac{7}{24}