The length of one side of a square field is represented by the expression 3 - 7x. a: write an expression for the perimeter of the field expression as a sum. b: what is an expression for the perimeter of the field expressed as a product. c: use the distributive property to write the product in part b as an equivalent expression

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?