Michael and his friend Justine enjoy hiking. Michael started up a mountain before Justine, so he's closer to the top when Justine starts hiking. Michael is 320 yards from the top and hikes 80 yards per hour. Justine is 390 yards from the top. But she doesn't know how many yards she hikes per hour. So every half hour, she writes down the yards left to hike in a table, as shown here.

Hours Spent Hiking
0.5
1
1.5
2
Yards from the top
330
270
210
150

Start by finding points for Michael's function. What are two points you could use to graph Michael's function for the yards left to hike in terms of the time he's spent hiking since Justine started?