2.287. Вычислите: а) 7/16 · 4/9 − 2/15; б) 8/15 · (2 1/2)^2 − 5/9; в) ((1 1/6)^2 − 7/18) · 2 4/7 − 1 2/5; г) (11/16 + 7/24 − 5/12) + (3/4)^2.

а) \(\frac{7}{16}\cdot\frac{4}{9}-\frac{2}{15}=\frac{7}{36}-\frac{2}{15}=\frac{35-24}{180}=\frac{11}{180}\).

б) \(\frac{8}{15}\cdot\left(2\frac{1}{2}\right)^2-\frac{5}{9}=\frac{8}{15}\cdot\frac{25}{4}-\frac{5}{9}=\frac{10}{3}-\frac{5}{9}=\frac{25}{9}=2\frac{7}{9}\).

в) \(\left(\left(1\frac{1}{6}\right)^2-\frac{7}{18}\right)\cdot2\frac{4}{7}-1\frac{2}{5}=\left(\frac{49}{36}-\frac{14}{36}\right)\cdot\frac{18}{7}-\frac{7}{5}=\frac{35}{36}\cdot\frac{18}{7}-\frac{7}{5}=\frac{5}{2}-\frac{7}{5}=\frac{11}{10}=1\frac{1}{10}\).

г) \(\frac{11}{16}+\frac{7}{24}-\frac{5}{12}+\left(\frac{3}{4}\right)^2=\frac{33+14-20}{48}+\frac{9}{16}=\frac{27}{48}+\frac{27}{48}=\frac{9}{8}=1\frac{1}{8}\).

Ответ: а) \(\frac{11}{180}\); б) \(2\frac{7}{9}\); в) \(1\frac{1}{10}\); г) \(1\frac{1}{8}\).