The table shows how an elevator 500 feet above the ground is descending at a steady rate. A two column table with 5 rows. The first column, time in seconds (t), has the entries, 0, 5, 10, 15. The second column, Height in feet h(t), has the entries, 500, 475, 450, 425. Which equation represents the height, h(t), of the elevator in feet, as a function of t, the number of seconds during which it has been descending?