Correct. If $\displaystyle{7}{x}+{y}={12}\usepackage{cmbright}\Huge\$ , then $\displaystyle{y}=-{7}{x}+{12}\usepackage{cmbright}\Huge\$ and this line has slope -7. Since the line $\displaystyle{y}={7}{x}+{4}\usepackage{cmbright}\Huge\$ has slope 7, the two lines are not parallel.