Rate of change is the same slope
To find the slope, pick any two point from the line and then locate its coordinates
(0, 1) and (1, -1)
x₁ = 0 y₁=1 x₂ = 1 y₂=-1
substitute the values into the formula below;
[tex]\text{slope =}\frac{y_2-y_1}{x_2-x_1}[/tex]
[tex]=\frac{-1-1}{1-0}[/tex]
[tex]=-2[/tex]
