find average rate of change of f(x)=2x from x[1]=0 to x[2]=5

Question

find average rate of change for this function f(x)=2x from x[1]=0 to x[2]=5

Answer 1

Average rate of Change of a function is (ƒ(x₂) - ƒ(x₁))/(x₂ - x₁)
                                               -----> (2 · 5 - 2 · 0)/(5 - 0) = 10/5 = 2
In case of direct variation (y=kx) the average rate of change is always "k"

Answer 2

The average rate of change is the change in y divided by the change in x for these two points. But this one can be solved simply by inspection. Hint: what is the definition of a slope?