3. Вычислите: а) 1 7/18 − 4/15; б) 4 4/5 : 4 1/6; в) 3 1/9 : 4 2/3; г) (30 : 27 − 1/3) · 2 1/7 + 2/5.

а) \(1\frac{7}{18}-\frac{4}{15}=\frac{25}{18}-\frac{4}{15}=\frac{125-24}{90}=\frac{101}{90}=1\frac{11}{90}\).

б) \(4\frac{4}{5}:4\frac{1}{6}=\frac{24}{5}:\frac{25}{6}=\frac{24}{5}\cdot\frac{6}{25}=\frac{144}{125}=1\frac{19}{125}\).

в) \(3\frac{1}{9}:4\frac{2}{3}=\frac{28}{9}:\frac{14}{3}=\frac{28}{9}\cdot\frac{3}{14}=\frac{2}{3}\).

г) \((30:27-\frac{1}{3})\cdot2\frac{1}{7}+\frac{2}{5}=\left(\frac{10}{9}-\frac{1}{3}\right)\cdot\frac{15}{7}+\frac{2}{5}=\frac{7}{9}\cdot\frac{15}{7}+\frac{2}{5}=\frac{5}{3}+\frac{2}{5}=\frac{31}{15}=2\frac{1}{15}\).

Ответ: а) \(1\frac{11}{90}\); б) \(1\frac{19}{125}\); в) \(\frac{2}{3}\); г) \(2\frac{1}{15}\).