With number 11 by the way

15 points ! ~ see if you know the answer to both you!

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

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?