Correct. If $\displaystyle{3}{x}-{4}{y}={8}\usepackage{cmbright}\Huge\$ , then $\displaystyle{3}{x}-{8}={4}{y}\usepackage{cmbright}\Huge\$ , so $\displaystyle{y}=\frac{{3}}{{4}}{x}-{2}\usepackage{cmbright}\Huge\$ and this line has slope $\displaystyle\frac{{3}}{{4}}\usepackage{cmbright}\Huge\$ . Since the line $\displaystyle{y}+{4}=-\frac{{3}}{{4}}{\left({x}-{2}\right)}\usepackage{cmbright}\Huge\$ has slope $\displaystyle-\frac{{3}}{{4}}\usepackage{cmbright}\Huge\$ , the two lines are not parallel.