Can you help me please?

What is the first step of an indirect proof of a number that is divisible by two

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 rectangle klmn, km = 6x + 16 and ln = 49. find the value of x