Упр.148 Часть 1 ГДЗ Дорофеев Петерсон 6 класс (Математика)

Тест 1.

$$3\frac{5}{6}-2\frac{8}{15}=3\frac{25}{30}-2\frac{16}{30}=1\frac{9}{30}=1\frac{3}{10}$$
$$3\frac{7}{15}+\frac{2}{3}=3\frac{7}{15}+\frac{10}{15}=3\frac{17}{15}=4\frac{2}{15}$$
$$7-3\frac{4}{9}=6\frac{9}{9}-3\frac{4}{9}=3\frac{5}{9}$$
$$5\frac{1}{8}-4\frac{3}{5}=5\frac{5}{40}-4\frac{24}{40}=4\frac{45}{40}-4\frac{24}{40}=\frac{21}{40}$$

Тест 2.

$$\frac{3}{14}\cdot 21=\frac{3\cdot 21}{14}=\frac{3\cdot 3}{2}=\frac{9}{2}=4\frac{1}{2}$$
$$2\frac{5}{6}\cdot 12=\frac{17}{6}\cdot 12=17\cdot 2=34$$
$$\frac{12}{7}:4=\frac{12}{7\cdot 4}=\frac{3}{7}$$
$$6\frac{2}{5}:2=\frac{32}{5}\cdot \frac{1}{2}=\frac{16}{5}=3\frac{1}{5}$$
$$\frac{10}{27}\cdot \frac{9}{25}=\frac{10\cdot 9}{27\cdot 25}=\frac{2\cdot 1}{3\cdot 5}=\frac{2}{15}$$
$$1\frac{7}{9}\cdot 3\frac{3}{4}=\frac{16}{9}\cdot \frac{15}{4}=\frac{16\cdot 15}{9\cdot 4}=\frac{4\cdot 5}{3\cdot 1}=\frac{20}{3}=6\frac{2}{3}$$
$$5\frac{1}{4}:\frac{7}{18}=\frac{21}{4}\cdot \frac{18}{7}=\frac{21\cdot 18}{4\cdot 7}=\frac{3\cdot 9}{2\cdot 1}=\frac{27}{2}=13\frac{1}{2}$$
$$\frac{3}{8}\cdot 2\frac{2}{3}:\frac{11}{15}\cdot 2\frac{1}{5} =\frac{3}{8}\cdot \frac{8}{3}:\frac{11}{15}\cdot \frac{11}{5} =1:\frac{121}{75} =\frac{75}{121}$$

Ответ

Тест 1: $$1\frac{3}{10};\ 4\frac{2}{15};\ 3\frac{5}{9};\ \frac{21}{40}.$$
Тест 2: $$4\frac{1}{2};\ 34;\ \frac{3}{7};\ 3\frac{1}{5};\ \frac{2}{15};\ 6\frac{2}{3};\ 13\frac{1}{2};\ \frac{75}{121}.$$