Savrup has drawn a graph to illustrate the linear relation between the cost of attending movies and the number of movies a person attends at Cineplex. Cineplex charges a membership fee of $25. It then costs $ 15 for every movie he attends. Cineplex has decided to change its price structure. It plans to increase the membership to $ 40, and reduce the charge per movie is $ 12. 

1.What effect will this change bring in terms of slope and y-intercept? 

2.(a) Is the relationship between the number of movies and the cost linear or nonlinear? (b) Explain your decision (This time, you need to say more than they form a straight line) 

3.(a) Is the relationship between the number of movies and the cost a direct variation or a partial variation? (b) Explain your decision.