Divide both sides of the equation by $\displaystyle-{6}\usepackage{cmbright}\Huge\$ :

$\displaystyle\frac{{-{6}{x}}}{{-{6}}}=\frac{{48}}{{-{6}}}\usepackage{cmbright}\Huge\$ , so $\displaystyle{x}=-{8}\usepackage{cmbright}\Huge\$ .