\[0,5x^{2} - x - 0,5 = 0\ \ \ \ \ | \cdot 2\]
\[x^{2} - 2x - 1 = 0\]
\[D = 1 + 1 = 2\]
\[x_{1} = 1 - \sqrt{2};\ \ \ x_{2} = 1 + \sqrt{2}\]
\[Ответ:x = 1 \pm \sqrt{2}.\]