\[x² - 8x + 7 = 0\]
\[x_{1} + x_{2} = 8;\ \ \ x_{1} \cdot x_{2} = 7\]
\[x_{1} = 7,\ \ x_{2} = 1\]
\[x² - 8x + 7 = (x - 7)(x - 1).\]