Graph the budget line for each of the following circumstances. 
a. Consider Robert's choice between watching movies on Netflix and all other consumption goods. Movies cost $4 to watch on Netflix. Robert has cash income of $40 and a $20 Netflix gift card, which cannot be resold and must be used entirely during the current period.
b. Nikki purchases food and clothes and works at a clothing store. Her income is $200, the price of food is $10, and the price of clothes is $40. Nikki receives an employee discount of the following form: She gets 50% off the price of all clothes items after purchasing 2 at the regular price.