\[x^{2} - 13x + 5 = 0\ \ \]
\[x_{1} + x_{2} = 13;\ \ \ x_{1} \cdot x_{2} = 5.\]
\[x_{1}^{3} + x_{2}^{3} =\]
\[= \left( x_{1} + x_{2} \right)\left( x_{1}^{2} - x_{1}x_{2} + x_{2}^{2} \right) =\]
\[= 13 \cdot \left( 13^{2} - 3 \cdot 5 \right) =\]
\[= 13 \cdot (169 - 15) = 13 \cdot 154 =\]
\[= 2002.\]