Answer:
slope is undefined
Step-by-step explanation:
Calculate the slope m using the gradient formula
m = ( y₂ - y₁ ) / ( x₂ - x₁ )
with (x₁, y₁ ) = (0, 3) and (x₂, y₂ ) = (0, - 5)
m =
= 
Division by 0 is undefined, hence slope is undefined
In fact this is the slope of a vertical line