Pls help me answer this question for my homework

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?

The difference between two numbers is one. three times the larger number minus two times the smaller number is 9. what are the two numbers

What is the name of a polygon that has four congruent sides and theses angle measures 60,120,60,120?