\[\ \frac{(x - 5)(x + 4)}{2x - 10} = 0\]
\[\frac{(x - 5)(x + 4)}{2 \cdot (x - 5)} = 0\]
\[x + 4 = 0\]
\[x = - 4\]
\[ОДЗ:x \neq 5\]
\[Ответ:\ x = - 4.\]
\[b > 0\ \ и\ \ c < 0\]
\[\ b^{4}c^{5} < 0\]
\[b^{4} > 0;\ \ \ c^{5} < 0.\]