Given g(x) = sqrt x-4 and h(x) = 2x-8 what is g(h(10))

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?

Which one is the correct answer, and why?

Which will form a composite function?