\[5x^{2} - 5x - 10 =\]
\[= 5 \cdot \left( x^{2} - x - 2 \right) =\]
\[= 5 \cdot (x - 2)(x + 1)\]
\[x^{2} - x - 2 = 0\]
\[x_{1} + x_{2} = 1;\ \ x_{1} \cdot x_{2} = - 2\]
\[x_{1} = 2;\ \ x_{2} = - 1.\]