39. Выполните действия: а) $(3\frac{7}{30}-1\frac{5}{12}):18\frac{1}{6}$; б) $(1,5+2\frac{2}{3}):1\frac{2}{3}$; в) $(\frac{11}{18}-1\frac{7}{12})\cdot(2\frac{1}{6}+\frac{7}{30})$; г) $(3,4-5)\cdot(\frac{31}{48}+\frac{7}{24})$.

Question

$Фото задания: 39. Выполните действия: а) $(3\frac{7}{30}-1\frac{5}{12}):18\frac{1}{6}$; б) $(1,5+2\frac{2}{3}):1\frac{2}{3}$; в)…$ Фото задания

Accepted Answer

а)
\[\left(3\frac{7}{30}-1\frac{5}{12}\right):18\frac{1}{6}=\left(\frac{97}{30}-\frac{17}{12}\right):\frac{109}{6}\]
\[=\left(\frac{194}{60}-\frac{85}{60}\right)\cdot\frac{6}{109}=\frac{109}{60}\cdot\frac{6}{109}=\frac{1}{10}.\]
б)
\[\left(1,5+2\frac{2}{3}\right):1\frac{2}{3}=\left(\frac{3}{2}+\frac{8}{3}\right):\frac{5}{3}\]
\[=\frac{25}{6}\cdot\frac{3}{5}=\frac{5}{2}=2,5.\]
в)
\[\left(\frac{11}{18}-1\frac{7}{12}\right)\cdot\left(2\frac{1}{6}+\frac{7}{30}\right)=\left(\frac{11}{18}-\frac{19}{12}\right)\cdot\left(\frac{13}{6}+\frac{7}{30}\right)\]
\[=\left(\frac{22}{36}-\frac{57}{36}\right)\cdot\left(\frac{65}{30}+\frac{7}{30}\right)=\left(-\frac{35}{36}\right)\cdot\frac{12}{5}=-\frac{7}{3}.\]
г)
\[(3,4-5)\cdot\left(\frac{31}{48}+\frac{7}{24}\right)=\left(-\frac{8}{5}\right)\cdot\left(\frac{31}{48}+\frac{14}{48}\right)\]
\[=-\frac{8}{5}\cdot\frac{45}{48}=-\frac{8}{5}\cdot\frac{15}{16}=-\frac{3}{2}.\]

Ответ: а) $\frac{1}{10}$; б) $2,5$; в) $-\frac{7}{3}$; г) $-\frac{3}{2}$.

39. Выполните действия: а) \((3\frac{7}{30}-1\frac{5}{12}):18\frac{1}{6}\); б) \((1,5+2\frac{2}{3}):1\frac{2}{3}\); в) \((\frac{11}{18}-1\frac{7}{12})\cdot(2\frac{1}{6}+\frac{7}{30})\); г) \((3,4-5)\cdot(\frac{31}{48}+\frac{7}{24})\).