The sequation to calculate the slope is,
[tex]m=\frac{y2-y1}{x2-x1}[/tex]The solpe of line joining (-1,2) and (4,2) is,
[tex]\begin{gathered} m=\frac{2-2}{4+1} \\ m=0 \end{gathered}[/tex]The slope of the line joining (-2,-2) and (0,4) is,
[tex]\begin{gathered} m=\frac{4+2}{0+2} \\ m=3 \end{gathered}[/tex]The slope of the line joining (1,3) and (-1,4) is,
[tex]\begin{gathered} m=\frac{4-3}{-1-1} \\ m=-\frac{1}{2} \end{gathered}[/tex]Negative slope.
The slope of the line joining (2,4) and (-2,-1) is,
[tex]\begin{gathered} m=\frac{-1-4}{-2-2} \\ m=\frac{5}{4} \end{gathered}[/tex]Positive slope.