PLS HELP I NEED THIS SOON

What is the missing reason in step 5? linear pair postulategivendefinition of complementary anglescongruent complements theorem

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?

Select the number of ways in which a line and a circle can intersect