Question

[(1-2/15):4/5]:[(2 và 5/7-1 và 1/6):1/42]

Answer 1

\(\left[\left(1-\frac{2}{15}\right):\frac{4}{5}\right]:\left[\left(2.\frac{5}{7}-1.\frac{1}{6}\right):\frac{1}{42}\right]\)

\(=\left[\left(\frac{15}{15}-\frac{2}{15}\right):\frac{4}{5}\right]:\left[\left(\frac{19}{7}-\frac{7}{6}\right):\frac{1}{42}\right]\)

\(=\left[\frac{3}{15}:\frac{4}{5}\right]:\left[\left(\frac{114}{42}-\frac{49}{42}\right):\frac{1}{42}\right]\)

\(=\left[\frac{3}{15}:\frac{4}{5}\right]:\left[\frac{65}{42}:\frac{1}{42}\right]\)

\(=\left[\frac{3}{15}.\frac{5}{4}\right]:\left[\frac{65}{42}.42\right]\)

\(=\frac{1}{4}:65\)

\(=\frac{1}{14}.\frac{1}{65}\)

\(=\frac{1}{910}\)