1. Вычислите: 1) 1 7/15 − 4/25; 2) 6 3/4 · 1 7/9; 3) 3 1/5 : 2 2/5; 4) (48 : 45 − 1/3) · 2 3/11 + 3/5.

1) \(1\dfrac{7}{15}-\dfrac{4}{25}=1+\dfrac{35}{75}-\dfrac{12}{75}=1\dfrac{23}{75}=\dfrac{98}{75}\).

2) \(6\dfrac{3}{4}\cdot1\dfrac{7}{9}=\dfrac{27}{4}\cdot\dfrac{16}{9}=12\).

3) \(3\dfrac{1}{5}:2\dfrac{2}{5}=\dfrac{16}{5}:\dfrac{12}{5}=\dfrac{16}{5}\cdot\dfrac{5}{12}=\dfrac{4}{3}=1\dfrac{1}{3}\).

4) \((48:45-\dfrac{1}{3})\cdot2\dfrac{3}{11}+\dfrac{3}{5}=(\dfrac{16}{15}-\dfrac{5}{15})\cdot\dfrac{25}{11}+\dfrac{3}{5}=\dfrac{11}{15}\cdot\dfrac{25}{11}+\dfrac{3}{5}=\dfrac{5}{3}+\dfrac{3}{5}=\dfrac{34}{15}=2\dfrac{4}{15}\).

Ответ: 1) \(1\dfrac{23}{75}\); 2) 12; 3) \(1\dfrac{1}{3}\); 4) \(2\dfrac{4}{15}\).