\[\boxed{\text{27\ (27).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ 0,3x = 9\]
\[x = \frac{9}{0,3}\]
\[x = \frac{90}{3}\]
\[x = 30\]
\[Ответ:\ x = 30.\]
\[2) - 2x = 3\]
\[x = - \frac{3}{2}\]
\[x = - 1,5\]
\[Ответ:\ x = - 1,5.\]
\[3)\ 15x = 0\]
\[x = 0\ :15\]
\[x = 0\]
\[Ответ:x = 0.\]