Correct. Multiply both sides of the equation by 10: $\displaystyle{10}{\left({13.1}-{0.7}{z}\right)}={10}{\left({8.2}\right)}\usepackage{cmbright}\Huge\$

Apply the distributive property and simplify: $\displaystyle{131}-{7}{z}={82}\usepackage{cmbright}\Huge\$

Subtract 131 from both sides: $\displaystyle-{7}{z}=-{49}\usepackage{cmbright}\Huge\$

Divide both sides by $\displaystyle-{7}\usepackage{cmbright}\Huge\$ : $\displaystyle{z}={7}\usepackage{cmbright}\Huge\$