$\{\begin{array}{l}x=\frac{4+2m+m^2}{2+m}\\ y=\frac{-4m}{2+m}\end{array}$                       $\left|x+y\right|<2$

$\left|\frac{4+2m+m^2}{2+m}+\frac{-4m}{2+m}\right|<2$
$\left|\frac{m^2-2m+4}{2+m}\right|<2$