(1, 1) and (4, -4)
Slope formula is : m = (y₂-y₁) / (x₂-x₁)
In this case :
x₁ = 1 ; x₂ = 4 ; y₁ = 1 ; y₂ = -4
Now that you know what variable counts as what, we simply just need to plug everything in.
m = (-4 - 1) / (4 - 1)
Simplify.
m = -5/3
Therefore, your slope is -5/3
~Hope I helped~ :)