Correct. Two lines are parallel if they have the same slope. By first expressing the line in slope intercept form, we can determine its slope. If $\displaystyle{x}+{2}{y}={4}\usepackage{cmbright}\Huge\$ , then $\displaystyle{2}{y}=-{x}+{4}\usepackage{cmbright}\Huge\$ , so $\displaystyle{y}=-\frac{{1}}{{2}}{x}+{2}\usepackage{cmbright}\Huge\$ . The slope of a parallel line will also be $\displaystyle-\frac{{1}}{{2}}\usepackage{cmbright}\Huge\$ .