\[x^{2} + 10x + 4 = 0\]
\[x_{1} + x_{2} = - 10;\ \ x_{1} \cdot x_{2} = 4\]
\[x_{1}^{2} + x_{2}^{2} =\]
\[= x_{1}^{2} + 2x_{1}x_{2} + x_{2}^{2} - 2x_{1}x_{2} =\]
\[= \left( x_{1} + x_{2} \right)^{2} - 2x_{1}x_{2} =\]
\[= ( - 10)^{2} - 2 \cdot 4 = 100 - 8 = 92.\]
\[Ответ:\ 92.\]