\[\ (2 - 7x)(5 + 4x) = 0\]
\[2 - 7x = 0\]
\[- 7x = - 2\]
\[x = \frac{2}{7}\]
\[5 + 4x = 0\]
\[4x = - 5\]
\[x = - \frac{5}{4} = - 1\frac{1}{4}\]
\[Ответ:\ \ x = \frac{2}{7}\ \ и\ \ x = - 1\frac{1}{4}.\]