Which system of equations match the graph?

A. Y=3x

y=x+3

B. Y=4x+2

y=3x+2

C. Y=2x+1

y=x+2

D. Y=2x+3

y=x+5

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?