Adisplay of gift boxes have one box in the top row three boxes in the next row 5 boxes in the next row and so on there are 7 rows and know how many gift boxes are there in display

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

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 anwser cause i do not understand just plez