a shopkeeper marked price a article a certain price above the cost price and he allowed 16% discount to make 5% profit if a customer paid 9492 with 13% vat to buy it by what percent is the mp above cp​

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?