Д.З. 1) \(18/35:12+11/10\); \(27/40:18+9/16\); \(9/14*(17/24-5/12)\); \(7/39*(1/7+6/49)\).

1) \(\frac{18}{35}:12+\frac{11}{10}=\frac{18}{35}\cdot\frac{1}{12}+\frac{11}{10}=\frac{3}{70}+\frac{77}{70}=\frac{8}{7}\).

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

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) \(\frac{7}{39}\cdot\left(\frac{1}{7}+\frac{6}{49}\right)=\frac{7}{39}\cdot\left(\frac{7}{49}+\frac{6}{49}\right)=\frac{7}{39}\cdot\frac{13}{49}=\frac{1}{21}\).

Ответ: 1) \(\frac{8}{7}\); 2) \(\frac{3}{5}\); 3) \(\frac{3}{16}\); 4) \(\frac{1}{21}\).