An electrician charges $15 plus $11 per hour. Another electrician charges $10 plus $15 per hour. Which of the systems of equations below correctly represents this situation if x represents the number of hours and y represents the total cost?

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?