\[2x^{2} + bx - 6 = 0;\ \ \ \ x_{1} = - 6.\]
\[x_{1} \cdot x_{2} = - \frac{6}{2}\]
\[- 6x_{2} = - 3\]
\[x_{2} = \frac{1}{2}.\]
\[x_{1} + x_{2} = - \frac{b}{2}\]
\[- 6 + \frac{1}{2} = - \frac{b}{2}\]
\[- \frac{b}{2} = - 5,5\]
\[b = 11.\]
\[Ответ:x_{2} = 0,5;\ \ b = 11.\]