Maybe something like 24/4=6. so sorry if I'm incorrect.
slope = - 
calculate the slope m using the gradient formula
m= (y₂ - y₁ ) / (x₂ - x₁ )
with (x₁, y₁ ) = (0, 4) and (x₂, y₂ ) = (- 3, 6)
m =
=
= - 
Infinitely many, because if you simplified the right side, it would equal the left side.