$\displaystyle{\left(-{2},{4}\right)}\usepackage{cmbright}\Huge\$ and $\displaystyle{\left({0},{0}\right)}\usepackage{cmbright}\Huge\$ are solutions for the system because they are solutions to both inequalities. However, $\displaystyle{\left(-{3},-{1}\right)}\usepackage{cmbright}\Huge\$ is not a solution for the system, as it is a solution to only the first inequality. If you substitute $\displaystyle-{1}\usepackage{cmbright}\Huge\$ into the second inequality you get $\displaystyle-{1}>-{1}\usepackage{cmbright}\Huge\$ , which is false.