\[x_{1} = 2;\text{\ \ \ \ }x_{2} = - \frac{1}{2}\]
\[\left( x - x_{1} \right)\left( x - x_{2} \right) = 0\]
\[(x - 2)\left( x + \frac{1}{2} \right) = 0\]
\[x^{2} + \frac{1}{2}x - 2x - 1 = 0\ \ \ |\text{·}2\]
\[2x^{2} + x - 4x - 2 = 0\]
\[2x^{2} - 3x - 2 = 0.\]
\[Ответ:2x^{2} - 3x - 2 = 0.\]