Answer:
Step-by-step explanation:
[tex]slope=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
It means that for a line passing through two points to have the slope, the x-coordinates of these point have to be different.
(-4, 0) and (-4, -10) means x₁ = x₂ = -4, so there is no slope.
{the line is parallel to Y-axis, and has an equation: x=-4}