Help please. need it asap

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?

In a singing competition, there are 150 participants. at the end of each round, 40% of the participants are eliminated. how many participants are left after n rounds?

One of the complementary angles is 4 degrees mor than the other. find the angles (recall that complementary angles are angles whose sum is 90 degrees.) which of the following can not be used to solve the problem if x represents one of the angles? a. 2x-4=90 b. 2x+4=90 c. x+4=90