Let:
[tex]\begin{gathered} (x1,y1)=(-12,3) \\ (x2,y2)=(-8,2) \end{gathered}[/tex]The slope m is given by:
[tex]m=\frac{y2-y1}{x2-x1}=\frac{2-3}{-8-(-12)}=\frac{-1}{4}=-\frac{1}{4}[/tex]So, we can conclude the slope of the line from point B to point A is -1/4