\[\boxed{\mathbf{1163\ (1155)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\frac{x}{12} - \frac{x}{8} = \frac{7}{6}\ \ | \cdot 24\]
\[2x - 3x = 28\]
\[- x = 28\]
\[x = - 28\]
\[Ответ:\ - 28.\]
\[2)\frac{13x}{21} + \frac{9x}{14} = - 1\ \ \ | \cdot 42\]
\[26x + 27x = - 42\]
\[53x = - 42\]
\[x = - \frac{42}{53}\]
\[Ответ:\ - \frac{42}{53}.\]
\[3) - \frac{3x}{10} - \frac{7}{15} = \frac{x}{6}\ \ | \cdot 30\]
\[9x - 14 = 5x\]
\[5x + 9x = - 14\]
\[14x = - 14\]
\[x = - 1\]
\[Ответ:\ - 1.\]