Slope of line is:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
(A)
for graph (A) x is constent that mean:
[tex]x_2=x_1[/tex]
so first line slope is infinty .
(B)
Forgraph B y is constent so:
[tex]y_2=y_1[/tex]
then slope is:
[tex]\begin{gathered} m=\frac{y_2-y_1}{x_2-x_1} \\ y_2=y_1 \\ m=0 \end{gathered}[/tex]
Slope of line is zero.
(C)
For graph (C)
[tex]\begin{gathered} m=\frac{y_2-y_1}{x_2-x_1}_{} \\ y_1>y_2 \end{gathered}[/tex]
So slope is negative ( that mean line slope is below zero.)
