Use the inverse variation equation $\displaystyle{y}=\frac{{k}}{{x}}\usepackage{cmbright}\Huge\$ : $\displaystyle{14}=\frac{{k}}{{6}}\usepackage{cmbright}\Huge\$ , so $\displaystyle{k}={84}\usepackage{cmbright}\Huge\$ .

Substitute 12 and 7: $\displaystyle{12}=\frac{{k}}{{7}}\usepackage{cmbright}\Huge\$ also yields $\displaystyle{k}={84}\usepackage{cmbright}\Huge\$ , so this is an inverse relationship.