An art class is making a mural for their school which has a triangle drawn in the middle. The length of the bottom of the triangle is x . Another side is 6 more than two times the length of the bottom of the triangle. The last side is 6 more than the bottom of the triangle. Write and simplify an expression for the perimeter of the triangle.

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?