How would the expression x^2-4 be rewritten using difference of squares? a) (x+2)^2 b) (x-4)^2 c) (x+4)(x-4) d) (x+2)(x-2)

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?