Д.З. 1. Вычислите: 1) 18/35 : 12 + 1/10; 2) 27/40 : 18 + 9/16; 3) 9/14 · (17/24 − 5/12); 4) 7/39 · (1/7 + 6/49).

1. \(\frac{18}{35}:12+\frac{1}{10}=\frac{18}{35}\cdot\frac{1}{12}+\frac{1}{10}=\frac{3}{70}+\frac{7}{70}=\frac{10}{70}=\frac{1}{7}\).

2. \(\frac{27}{40}:18+\frac{9}{16}=\frac{27}{40}\cdot\frac{1}{18}+\frac{9}{16}=\frac{3}{80}+\frac{45}{80}=\frac{48}{80}=\frac{3}{5}\).

3. \(\frac{9}{14}\cdot\left(\frac{17}{24}-\frac{5}{12}\right)=\frac{9}{14}\cdot\left(\frac{17}{24}-\frac{10}{24}\right)=\frac{9}{14}\cdot\frac{7}{24}=\frac{3}{16}\).

4. \(\frac{7}{39}\cdot\left(\frac{1}{7}+\frac{6}{49}\right)=\frac{7}{39}\cdot\left(\frac{7}{49}+\frac{6}{49}\right)=\frac{7}{39}\cdot\frac{13}{49}=\frac{1}{3}\).

Ответ: 1) \(\frac{1}{7}\); 2) \(\frac{3}{5}\); 3) \(\frac{3}{16}\); 4) \(\frac{1}{3}\).