Answer
The variables are Area Painted and Amount of Paint in the Can.
The graph shows that as the area painted increases, the amount of paint in the can decreases. The rate of decrease is constant until the can is eventually empty.
Work Step by Step
Area Painted is the variable on the x axis. Amount of Paint in the Can is on the y axis. A graph shows the relationship of changes in the variable on the x axis and changes in the variable on the y axis. The x axis increases as you move to the right. The y axis increases as you move up.