y = mx + b, where m= slope and b = y-intercept
y = (1/3)x - 4
Slope is change in y/chasnge on x. Start with your point on the y-intercept at (0,-4), go up 1 and right 3 for your next point.
Since -1/-3 = 1/3, you can also go down 1 and left 3 for another point.