\[y = 3x^{2} + x - 17\]
\[y > 0\ при\ \]
\[x \in ( - \infty; - 2,5) \cap (2,5; + \infty)\ \]
\[y < 0\ при\ x( - 2,5;2,5).\]
\[y = - 2x^{2} - 5x + 12\]
\[y > 0\ при\ x \in ( - 4;1,5);\]
\[y < 0\ при\ \]
\[x \in ( - \infty; - 4) \cup (1,5; + \infty).\]