\[b² - 15b + 14 = 0\]
\[b_{1} + b_{2} = 15;\ \ b_{1} \cdot b_{2} = 14\]
\[b_{1} = 14,\ \ b_{2} = 1.\]
\[b^{2} - 15b + 14 =\]
\[= (b - 14)(b - 1).\]