Which point could be removed in order to make the relation a function

If f(x)= 3x+6 which of the following is the inverse of f(x)

Complete the equation of the line through (−10,3) and (−8,−8). use exact numbers.

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?