\[x^{2} - x - 6 = 0\]
\[x_{1} + x_{2} = 1\]
\[x_{1} \cdot x_{2} = - 6\]
\[\Longrightarrow x_{1} = - 2;\ \ x_{2} = 3.\]
\[x² - x - 6 = (x + 2)(x - 3).\]