Please explain and need help as soon as possible

Factor -8x3-2x2-12x-3 by grouping what is the resulting expression?

Ling listed all of the factors of a mystery number: 1,2,4,8,16,32 what is the mystery number?

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?