Answer:
The graphs for the lines of the costs are in the attachment. For this answer you have to first determine the equations for each cost. Since Hammy's Froyo charges $2.40 for the container and $.40 for each ounce, the equation would be y=.40x+2.40. For Yogurt Palace, which charges $0.80 for each ounce, the equation would be y=.80x.