You may have squared the left side and not the right side, to get the incorrect equation $\displaystyle{x}+{10}=-{4}\usepackage{cmbright}\Huge\$ . That equation would have $\displaystyle{x}=-{14}\usepackage{cmbright}\Huge\$ as a solution. Make sure that you always perform the same operation on both sides of an equation. The correct answer is that there is no solution.