\[2x^{2} - x - 15 > 0\]
\[D = 1 + 120 = 121\]
\[x_{1} = \frac{1 + 11}{4} = 3;\]
\[x_{2} = \frac{1 - 11}{4} = - \frac{10}{4} = - 2,5.\]
\[(x + 2,5)(x - 3) > 0\]
\[x < - 2,5;\ \ x > 3.\]
\[Ответ:x < - 2,5;x > 3.\]