remember the formula for the slope of the line
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]For the blue line
point 1= (-3,2)
point 2= (4,-1)
find the slope
[tex]\begin{gathered} m=\frac{-1-2}{4-(-3)} \\ m=-\frac{3}{7} \end{gathered}[/tex]For the red line
point 1= (2,5)
point 2= (2,-3)
find the slope
[tex]\begin{gathered} m=\frac{-3-5}{2-2} \\ m=-\frac{8}{0}=IND \end{gathered}[/tex]Since the denominator is equal to 0 we can say that the line has an undefined slope.