Multiply both sides of the equation by the multiplicative inverse of $\displaystyle-\frac{{1}}{{2}}\usepackage{cmbright}\Huge\$ , which is $\displaystyle-{2}\usepackage{cmbright}\Huge\$ :

$\displaystyle{\left(-{2}\right)}{\left(-\frac{{1}}{{2}}\right)}{x}={\left(-{2}\right)}{6}\usepackage{cmbright}\Huge\$ . Simplifying, $\displaystyle{\left(\frac{{2}}{{2}}\right)}{x}=-{12}\usepackage{cmbright}\Huge\$ or $\displaystyle{x}=-{12}\usepackage{cmbright}\Huge\$ .