1. ) A graph of a proportional relationship has a straight line that passes through the origin (0, 0).
2.) So....
a. This line is proportional. It passes through the origin and both x and y have a proportional relationship.
b. This line is not proportional. In (3, 3), the line suddenly goes up. Although it passes through the origin, it is not a straight line.
c. This line is not proportional. It has a straight line; but, the starting point is at (0, 3) and not (0, 0).
