\[x_{1} = - 4;\text{\ \ \ }x_{2} = \frac{1}{2}:\]
\[\left( x - x_{1} \right)\left( x - x_{2} \right) = 0\]
\[(x + 4)\left( x - \frac{1}{2} \right) = 0\]
\[x^{2} - \frac{1}{2}x + 4x - \frac{4}{2} = 0\ \ \ \ \ \ \ | \cdot 2\]
\[2x^{2} - x + 8x - 4 = 0\]
\[2x^{2} + 7x - 4 = 0.\]
\[Ответ:2x^{2} + 7x - 4 = 0.\]