2. а) 53 2/3 − 22 14/15 : 2 2/3; б) 3 1/10 − 1 5/9 · (2 1/4 − 1 7/8).

1. \(53\frac23-22\frac{14}{15}:2\frac23=\frac{161}{3}-\frac{344}{15}\cdot\frac38=\frac{161}{3}-\frac{43}{5}=\frac{805-129}{15}=\frac{676}{15}=45\frac1{15}\).
2. \(3\frac1{10}-1\frac59\cdot\left(2\frac14-1\frac78\right)=\frac{31}{10}-\frac{14}{9}\cdot\frac38=\frac{31}{10}-\frac7{12}=\frac{186-35}{60}=\frac{151}{60}=2\frac{31}{60}\).

Ответ: а) \(45\frac1{15}\); б) \(2\frac{31}{60}\).