№2. Найдите значение выражения: а) \( 3 \frac{5}{8} \times 1 \frac{7}{9} \times \frac{21}{58} \); б) \( (\frac{2}{9} + \frac{5}{6}) \times 36 \)

Решение:

1. а) \( 3 \frac{5}{8} \times 1 \frac{7}{9} \times \frac{21}{58} = \frac{3 \times 8 + 5}{8} \times \frac{1 \times 9 + 7}{9} \times \frac{21}{58} = \frac{29}{8} \times \frac{16}{9} \times \frac{21}{58} = \frac{29 \times 16 \times 21}{8 \times 9 \times 58} = \frac{29 \times (2 \times 8) \times (3 \times 7)}{8 \times (3 \times 3) \times (2 \times 29)} = \frac{7}{3} \)
2. б) \( (\frac{2}{9} + \frac{5}{6}) \times 36 = (\frac{2 \times 2}{9 \times 2} + \frac{5 \times 3}{6 \times 3}) \times 36 = (\frac{4}{18} + \frac{15}{18}) \times 36 = \frac{4 + 15}{18} \times 36 = \frac{19}{18} \times 36 = 19 \times 2 = 38 \)

Ответ: а) \( \frac{7}{3} \); б) \( 38 \).