2.379. Найдите значение выражения: а) \(\left(2\frac{1}{4}+1\frac{5}{6}\right)\cdot\left(4-3\frac{38}{49}\right)\); б) \(\left(2+3\frac{11}{18}\right)\cdot\left(20-17\frac{9}{16}\right)\); в) \(\left(2+1\frac{8}{9}\right)\cdot\left(3\frac{4}{5}-\frac{38}{55}\right)\); г) \(5\frac{13}{15}\cdot\frac{5}{11}-7\frac{1}{5}\cdot\frac{1}{6}\).

1. а) \(\left(\frac{9}{4}+\frac{11}{6}\right)\left(4-\frac{185}{49}\right)=\frac{49}{12}\cdot\frac{11}{49}=\frac{11}{12}\).
2. б) \(\left(2+\frac{65}{18}\right)\left(20-\frac{281}{16}\right)=\frac{101}{18}\cdot\frac{39}{16}=\frac{1313}{96}=13\frac{65}{96}\).
3. в) \(\left(2+\frac{17}{9}\right)\left(\frac{19}{5}-\frac{38}{55}\right)=\frac{35}{9}\cdot\frac{171}{55}=\frac{133}{11}=12\frac{1}{11}\).
4. г) \(\frac{88}{15}\cdot\frac{5}{11}-\frac{36}{5}\cdot\frac{1}{6}=\frac{8}{3}-\frac{6}{5}=\frac{22}{15}=1\frac{7}{15}\).

Ответ: а) \(\frac{11}{12}\); б) \(13\frac{65}{96}\); в) \(12\frac{1}{11}\); г) \(1\frac{7}{15}\).