3) (5/6 − 1/4) : 4/12 + 1/3 · 3/5 − 1/5

\(\left(\frac{5}{6}-\frac{1}{4}\right):\frac{4}{12}+\frac{1}{3}\cdot\frac{3}{5}-\frac{1}{5}\)

\(\frac{5}{6}-\frac{1}{4}=\frac{10}{12}-\frac{3}{12}=\frac{7}{12}\)

\(\frac{7}{12}:\frac{4}{12}=\frac{7}{12}\cdot\frac{12}{4}=\frac{7}{4}\)

\(\frac{1}{3}\cdot\frac{3}{5}=\frac{1}{5}\)

\(\frac{7}{4}+\frac{1}{5}-\frac{1}{5}=\frac{7}{4}\)

Ответ: \(\frac{7}{4}\)