Задание 1. Вычислите: 1) $\frac{2}{7}\cdot\frac{42}{5}$; 2) $\frac{3}{16}:\frac{5}{8}$; 3) $(\frac{7}{15}+\frac{19}{30})\cdot\frac{9}{11}$; 4) $(\frac{3}{25}-\frac{2}{35})\cdot14$; 5) $(1\frac{3}{17}+\frac{1}{34})\cdot17$; 6) $5\frac{2}{5}:(3\frac{1}{4}-2\frac{4}{5})$; 7) $1:(\frac{1}{28}+\frac{1}{12})$; 8) $40\cdot(\frac{1}{8})^2-13\frac{1}{8}$.

Question

Вопрос: $Фото задания: Задание 1. Вычислите: 1) $\frac{2}{7}\cdot\frac{42}{5}$; 2) $\frac{3}{16}:\frac{5}{8}$; 3)…$ Фото задания

Accepted Answer

$\frac{2}{7}\cdot\frac{42}{5}=\frac{12}{5}$.
$\frac{3}{16}:\frac{5}{8}=\frac{3}{16}\cdot\frac{8}{5}=\frac{3}{10}$.
$(\frac{7}{15}+\frac{19}{30})\cdot\frac{9}{11}=(\frac{14}{30}+\frac{19}{30})\cdot\frac{9}{11}=\frac{11}{10}\cdot\frac{9}{11}=\frac{9}{10}$.
$(\frac{3}{25}-\frac{2}{35})\cdot14=\frac{11}{175}\cdot14=\frac{22}{25}$.
$(1\frac{3}{17}+\frac{1}{34})\cdot17=(\frac{40}{34}+\frac{1}{34})\cdot17=\frac{41}{2}$.
$5\frac{2}{5}:(3\frac{1}{4}-2\frac{4}{5})=\frac{27}{5}:\frac{9}{20}=12$.
$1:(\frac{1}{28}+\frac{1}{12})=1:\frac{5}{42}=\frac{42}{5}$.
$40\cdot(\frac{1}{8})^2-13\frac{1}{8}=\frac{5}{8}-\frac{105}{8}=-\frac{25}{2}$.

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