请选择切换地区
设$A=\left\{ x\left| \frac{2x-1}{{{x}^{2}}+3x+2}>0 \right. \right\}$,$B=\left\{ x|{{x}^{2}}+ax+b\le 0 \right\}$,且$A\bigcap B=\left\{ x\left| \frac{1}{2}<x\le 3 \right. \right\}$,$a$,$b\in \mathbf{R}$,
则$a+b$的取值范围为__________
$\left[ -5,-2 \right]$