Given data:
The first point on the line is (a, b)=(-1, -1).
The second point on the line is (c, d)= ( 4, -5).
The slope of the line is,
[tex]m=\frac{d-b}{c-a}[/tex]Substitute the given values in the above expression.
[tex]\begin{gathered} m=\frac{-5-(-1)}{4-(-1)} \\ =\frac{-5+1}{4+1} \\ =\frac{-4}{5} \\ =-\frac{4}{5} \end{gathered}[/tex]Thus, the slope of the given line is -4/5.