Final answer:
The equation to find the total price Nicholas must pay for used movies and x new movies is y = 9.50x + u×2.50, where u is the number of used movies.
Step-by-step explanation:
The student is asking for an equation to find y, the total price Nicholas must pay in dollars for buying used movies and x new movies. New movies are sold at $9.50 each, and used movies are sold at $2.50 each. The total cost can be found by adding the cost of the new movies (x times $9.50) to the cost of the used movies. Therefore, the equation we are looking for would be y = 9.50x + (number of used movies) × 2.50. As the number of used movies Nicholas is buying isn't given, we can only assume it's a known constant and represent it with u, making the equation y = 9.50x + u× 2.50, where u is the number of used movies.