What would x be and what would y be

Me complete this proof! prove that a quadrilateral is a square. me with the steps for this proof.

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 two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16