First, you probably wrote the slope as $\displaystyle\frac{{{r}{u}{n}}}{{{r}{i}{s}{e}}}\usepackage{cmbright}\Huge\$ instead of $\displaystyle\frac{{{r}{i}{s}{e}}}{{{r}{u}{n}}}\usepackage{cmbright}\Huge\$ . Second, if you move from $\displaystyle{\left(-{4},-{3}\right)}\usepackage{cmbright}\Huge\$ to $\displaystyle{\left(-{1},-{2}\right)}\usepackage{cmbright}\Huge\$ , you are going up and to the right, so both the rise and the run are positive. This means that the slope is positive.