Problem 3
The graph looks perfect. Nice work.
===========================================================
Problem 4
The line should be completely horizontal and flat. There should be no diagonal slant to the line. Make sure every point on this line has a y coordinate of -2.
===========================================================
Problem 5
The x value x = 1 does not lead to y = 26. Instead it should lead to y = 29. Other than that, your table looks great.
You made an error with the graph. The x values don't start at 20. Instead you should start at x = 0. You might have mixed up x and y for the graph.