Find the area of the trapezoids

What values of c and d make the equation true?

F(x)= 4x g(x) =x-1 what is f(x) divided by g(x)

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?