Suppose you know the center of the circle and a point on the circle. how do you determine the equation of the circle

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?

Is a square always, sometimes, or never a parallelogram

Why is 4.125 + the square root of 3 irrational