Задание 135 Вариант 4 Самостоятельная работа ГДЗ Дидактические материалы Чесноков 6 класс (Математика)

а)

$$20+\left(7\frac{1}{3}-6\frac{7}{8}\right):\frac{3}{4}-\left(5\frac{1}{4}-4\frac{21}{40}\right):\frac{9}{20}$$
$$7\frac{1}{3}-6\frac{7}{8}=7\frac{8}{24}-6\frac{21}{24}=6\frac{32}{24}-6\frac{21}{24}=\frac{11}{24}$$
$$5\frac{1}{4}-4\frac{21}{40}=5\frac{10}{40}-4\frac{21}{40}=4\frac{50}{40}-4\frac{21}{40}=\frac{29}{40}$$
$$\frac{11}{24}:\frac{3}{4}=\frac{11}{24}\cdot\frac{4}{3}=\frac{11}{18}$$
$$\frac{29}{40}:\frac{9}{20}=\frac{29}{40}\cdot\frac{20}{9}=\frac{1}{2}$$
$$20+\frac{11}{18}-\frac{1}{2}=20+\frac{11}{18}-\frac{9}{18}=20+\frac{2}{18}=20\frac{1}{9}$$

б)

$$10-4\frac{1}{2}:2\frac{3}{4}+\left(2\frac{1}{2}-1\frac{1}{3}\right)\cdot 6$$
$$2\frac{1}{2}-1\frac{1}{3}=2\frac{3}{6}-1\frac{2}{6}=1\frac{1}{6}$$
$$2\frac{1}{2}:3\frac{3}{4}=\frac{5}{2}:\frac{15}{4}=\frac{5}{2}\cdot\frac{4}{15}=\frac{2}{3}$$
$$1\frac{1}{6}\cdot 6=\frac{7}{6}\cdot 6=7$$
$$10-\frac{2}{3}+7=17-\frac{2}{3}=16\frac{1}{3}$$

Ответ: а) $$20\frac{1}{9}$$; б) $$16\frac{1}{3}$$.