[tex]\bf \begin{array}{ccccccccc}
&&x_1&&y_1&&x_2&&y_2\\
% (a,b)
&&(~ -4 &,& 3~)
% (c,d)
&&(~ 6 &,& -3~)
\end{array}
\\\\\\
% slope = m
slope = m\implies
\cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{-3-3}{6-(-4)}\implies \cfrac{-3-3}{6+4}
\\\\\\
\cfrac{-6}{10}\implies -\cfrac{3}{5}[/tex]