Multiply both sides of the equation by the multiplicative inverse of $\displaystyle\frac{{1}}{{8}}\usepackage{cmbright}\Huge\$ , which is 8:

$\displaystyle{\left({8}\right)}{\left(\frac{{1}}{{8}}\right)}{x}={\left({8}\right)}{\left(-{8}\right)}\usepackage{cmbright}\Huge\$ . Simplifying, $\displaystyle{\left(\frac{{8}}{{8}}\right)}{x}=-{64}\usepackage{cmbright}\Huge\$ or $\displaystyle{x}=-{64}\usepackage{cmbright}\Huge\$ .