Movie mania requires customers to pay a sign-up fee of $20, and charges $4.00 to rent a dvd. hurricane video is free to join, but dvds cost $6.00 to rent. write and solve an equation to find the number of dvds you would have to rent in order for both stores to charge the same. explain what your variable represents. a. let n = the cost of renting a movie; 20n + 4 = 6; 40 videos b. let n = the number of dvds rented; 20 + 4n = 6n; 10 videos c. let n = the cost of renting a movie; 20n + 4 = 6; 2 videos d. let n = the number of dvds rented; 20 + 4n = 6n; 40 videos