Вычислите: 1/7 ÷ 2; 18/23 ÷ 9; 15/11 ÷ 5; 7/8 ÷ 5; 16/19 ÷ 5; 17/12 ÷ 7.

1. Делим числитель дроби на число: \(\frac{1}{7}\div2=\frac{1}{7\cdot2}=\frac{1}{14}\).
2. \(\frac{18}{23}\div9=\frac{18}{23\cdot9}=\frac{2}{23}\).
3. \(\frac{15}{11}\div5=\frac{15}{11\cdot5}=\frac{3}{11}\).
4. \(\frac{7}{8}\div5=\frac{7}{8\cdot5}=\frac{7}{40}\).
5. \(\frac{16}{19}\div5=\frac{16}{19\cdot5}=\frac{16}{95}\).
6. \(\frac{17}{12}\div7=\frac{17}{12\cdot7}=\frac{17}{84}\).

Ответ: \(\frac{1}{14};\ \frac{2}{23};\ \frac{3}{11};\ \frac{7}{40};\ \frac{16}{95};\ \frac{17}{84}\).