Step 1: If the equal interval length is k, the two endpoints of the interval will be labeled ,0 and p + k. Label the endpoints of the corresponding interval on the yaxis of the graph below. Hint: First, substitute x z p intoy = mx + b. Next, substitute x =p + k into y = mx + b. (1) {y-value at x = p) (2) {yvalue at x = p + k) Step 3: Interpret your answer from Step 2 to prove that linear functions always grow by equal differences over equal intervals. Hint: Use these questions to justify your answer: . Does your answer to Step 2 depend on p? . What does it depend on? . Is the difference between the yvalues the same regardless of where the interval starts