方程 $\mathit{2}{\mathit{x}}^{\mathit{2}}\mathit{+}\mathit{3}\mathit{x}\mathit{-}\mathit{1}\mathit{=}\mathit{0}$的两个根为 ${\mathit{x}}_{\mathit{1}}$、 ${\mathit{x}}_{\mathit{2}}$，则 $\frac{\mathit{1}}{{\mathit{x}}_{\mathit{1}}}\mathit{+}\frac{\mathit{1}}{{\mathit{x}}_{\mathit{2}}}$的值等于　    　．