4. Just look at the graph, and see which coordinates are on the line.
D, E, and F are on the line.
5. The y-coordinate is (0,4), and the slope is (4 + 8)/(0 - 4) = -3. Therefore, the equation of the line is y = -3x + 4. Plugging in the numbers we know gives us b = -3*8 + 4. b = -20.
6. Find the number of times P is on a line. There are two lines that do so.
