Which of the following questions has a vertical stretch ?

Joe has a rectangular chicken coop. the length of the coop is 4 feet less than twice the width. the area of the chicken coop is 510 square feet. what is the length of the chicken coup?

Which one is the correct answer, and why?

If you apply the changes below to the linear parent function f(x)=x what is the equation of the new function vertically stretched by a factor of 3 flip over the x axis