Correct. If $\displaystyle{2}{x}+{y}={6}\usepackage{cmbright}\Huge\$ , then $\displaystyle{y}=-{2}{x}+{6}\usepackage{cmbright}\Huge\$ and this line has slope -2. Since the line $\displaystyle{y}={2}{x}+{4}\usepackage{cmbright}\Huge\$ has slope 2, the two lines are not parallel.