3.5

5: Subtract the y-values, and then subtract the x-values in the same order.

7: This line is flat—it does not go up or down.

9: Pick any two points, and do it the same as if you were looking at a graph (like #5).

10: The y value never changes, so the graph never gets higher or lower.

11: The y values goes up or down, but the x value always stays equal to 0.

13: Use the word “per” in your explanation of what the slope represents.

14: The y-value (price) doesn’t change no matter what the x-value (hours) is.

17: This is the same as y ＝ 6x + 0.

22: Start by adding 2y to each side, and then dividing each side by 2.

30: Find the y intercept by setting x equal to zero, and vice versa.