№4 Вычислите: а) 1/2 + (3/4 − 1/4) · 2; б) (5/6 − 1/3) : 1/2 + 1/3; в) ((3/5 + 1/5) · 2 − 1/5) : 3; г) 3/4 · (2/3 − (1/2 − 1/4)).

а) \(\frac{1}{2}+\left(\frac{3}{4}-\frac{1}{4}\right)\cdot2=\frac{1}{2}+\frac{1}{2}\cdot2=\frac{1}{2}+1=\frac{3}{2}\).

б) \(\left(\frac{5}{6}-\frac{1}{3}\right):\frac{1}{2}+\frac{1}{3}=\frac{1}{2}:\frac{1}{2}+\frac{1}{3}=1+\frac{1}{3}=\frac{4}{3}\).

в) \(\left(\left(\frac{3}{5}+\frac{1}{5}\right)\cdot2-\frac{1}{5}\right):3=\left(\frac{4}{5}\cdot2-\frac{1}{5}\right):3=\frac{7}{5}:3=\frac{7}{15}\).

г) \(\frac{3}{4}\cdot\left(\frac{2}{3}-\left(\frac{1}{2}-\frac{1}{4}\right)\right)=\frac{3}{4}\cdot\left(\frac{2}{3}-\frac{1}{4}\right)=\frac{3}{4}\cdot\frac{5}{12}=\frac{5}{16}\).

Ответ: а) \(\frac{3}{2}\); б) \(\frac{4}{3}\); в) \(\frac{7}{15}\); г) \(\frac{5}{16}\).