\[\boxed{\mathbf{189\ (189).}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[\frac{1}{2} = \frac{1 \cdot 4}{2 \cdot 4} = \frac{4}{8}\]
\[\frac{1}{3} = \frac{1 \cdot 4}{3 \cdot 4} = \frac{4}{12}\]
\[\frac{5}{6} = \frac{5 \cdot 4}{6 \cdot 4} = \frac{20}{24}\]
\[\frac{4}{7} = \frac{4 \cdot 4}{7 \cdot 4} = \frac{16}{28}\]
\[\frac{10}{19} = \frac{10 \cdot 4}{19 \cdot 4} = \frac{40}{76}\]
\[\boxed{\mathbf{189}\mathbf{.}}\]
\[Пара\ простых\ чисел,\ разность\ \]
\[которых\ равна\ 17:\]
\[2\ и\ 19.\]