Which of the following statements contain a variable? check all that apply. a. the number of people added to the group. b. half the area of the roof. c. sixteen feet long. d. she ran 40 yards

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?