\[\left\{ \begin{matrix}
5 + 19x - 4x^{2} > 0 \\
3x^{2} - x - 4
eq 0\ \ \\
\end{matrix} \right.\ \]
\[3x^{2} - x - 4
eq 0\]
\[D = 49\]
\[x
eq - 1,\ \ x
eq 1\frac{1}{3}\]
\[5 + 19x - 4x^{2} = 0\]
\[D = 361 + 80 = 441\]
\[x_{1} = 5,\ \ \ x_{2} = - 0,25\]