Combine like terms: $\displaystyle-{2}{x}+{7}={8}{x}-{7}\usepackage{cmbright}\Huge\$

Subtract 7 from both sides: $\displaystyle-{2}{x}={8}{x}-{14}\usepackage{cmbright}\Huge\$

Subtract $\displaystyle{8}{x}\usepackage{cmbright}\Huge\$ from both sides: $\displaystyle-{10}{x}=-{14}\usepackage{cmbright}\Huge\$

Divide both sides by $\displaystyle-{10}\usepackage{cmbright}\Huge\$ : $\displaystyle{x}=\frac{{-{14}}}{{-{10}}}=\frac{{7}}{{5}}\usepackage{cmbright}\Huge\$