Multiply the first equation by 2: $\displaystyle-{4}{x}+{2}{y}=-{32}\usepackage{cmbright}\Huge\$

Add this to $\displaystyle{4}{x}-{2}{y}={30}\usepackage{cmbright}\Huge\$ : $\displaystyle{0}=-{2}\usepackage{cmbright}\Huge\$

If both equations in the system were true, that would imply that $\displaystyle{0}=-{2}\usepackage{cmbright}\Huge\$ . Since this is false, you cannot find numbers that make both equations true. In other words, the system does not have a solution.