Вычисли выражения: a) 7/16 * 4/9 - 2/15; б) ((1 1/6)^2 - 7/18) * 2 4/7 - 1 2/5; в) 8/15 - (2 1/2)^2 - 5/9; г) (11/16 + 7/24 - 5/12) + (3/4)^2

a) $\frac{7}{16} \cdot \frac{4}{9} - \frac{2}{15} = \frac{7 \cdot 4}{16 \cdot 9} - \frac{2}{15} = \frac{7}{4 \cdot 9} - \frac{2}{15} = \frac{7}{36} - \frac{2}{15} = \frac{7 \cdot 5}{36 \cdot 5} - \frac{2 \cdot 12}{15 \cdot 12} = \frac{35}{180} - \frac{24}{180} = \frac{35 - 24}{180} = \frac{11}{180}$ б) $\left(\left(1\frac{1}{6}\right)^2 - \frac{7}{18}\right) \cdot 2\frac{4}{7} - 1\frac{2}{5} = \left(\left(\frac{7}{6}\right)^2 - \frac{7}{18}\right) \cdot \frac{18}{7} - \frac{7}{5} = \left(\frac{49}{36} - \frac{7}{18}\right) \cdot \frac{18}{7} - \frac{7}{5} = \left(\frac{49}{36} - \frac{14}{36}\right) \cdot \frac{18}{7} - \frac{7}{5} = \frac{35}{36} \cdot \frac{18}{7} - \frac{7}{5} = \frac{5}{2} - \frac{7}{5} = \frac{5 \cdot 5}{2 \cdot 5} - \frac{7 \cdot 2}{5 \cdot 2} = \frac{25}{10} - \frac{14}{10} = \frac{11}{10} = 1\frac{1}{10}$ в) $\frac{8}{15} - \left(2\frac{1}{2}\right)^2 - \frac{5}{9} = \frac{8}{15} - \left(\frac{5}{2}\right)^2 - \frac{5}{9} = \frac{8}{15} - \frac{25}{4} - \frac{5}{9} = \frac{8 \cdot 12}{15 \cdot 12} - \frac{25 \cdot 45}{4 \cdot 45} - \frac{5 \cdot 20}{9 \cdot 20} = \frac{96}{180} - \frac{1125}{180} - \frac{100}{180} = \frac{96 - 1125 - 100}{180} = \frac{-1129}{180} = -6\frac{49}{180}$ г) $\left(\frac{11}{16} + \frac{7}{24} - \frac{5}{12}\right) + \left(\frac{3}{4}\right)^2 = \left(\frac{11 \cdot 3}{16 \cdot 3} + \frac{7 \cdot 2}{24 \cdot 2} - \frac{5 \cdot 4}{12 \cdot 4}\right) + \frac{9}{16} = \left(\frac{33}{48} + \frac{14}{48} - \frac{20}{48}\right) + \frac{9}{16} = \frac{33 + 14 - 20}{48} + \frac{9}{16} = \frac{27}{48} + \frac{9}{16} = \frac{9}{16} + \frac{9}{16} = \frac{18}{16} = \frac{9}{8} = 1\frac{1}{8}$ **Ответы:** a) $\frac{11}{180}$ б) $1\frac{1}{10}$ в) $-6\frac{49}{180}$ г) $1\frac{1}{8}$