\[x^{2} + 2x - 3 < 0\]
\[x_{1} + x_{2} = - 2;\ \ x_{1} \cdot x_{2} = - 3\]
\[x_{1} = - 3;\ \ x_{2} = 1\]
\[(x + 3)(x - 1) < 0\]
\[x \in ( - 3;1).\]