\[x^{2} - 13x + 5 = 0\ \ \]
\[x_{1} + x_{2} = 13;\ \ \ x_{1} \cdot x_{2} = 5.\]
\[x_{1}^{2}x_{2} + x_{1}x_{2}^{2} = x_{1}x_{2}\left( x_{1} + x_{2} \right) =\]
\[= 5 \cdot 13 = 65.\]