I believe that the answer to this is k=0.0999
We know that the width of the garden is =
feet = 6.75 feet
and Perimeter of the garden is = 37.5 feet
Also, we know that for a rectangular space perimeter = 2 * (l + w)
⇒ 37.5 = 2 * (l + 6.75)
⇒ 37.5 = 13.5 + 2*l
⇒ 24 = 2*l
⇒ l = 12 feet
Now, we need to determine how much square feet of mulch is required, hence we need to calculate the area of the garden
Area = l * w
⇒ Area = 12 * 6.75
⇒ Area = 81 square feet
Hence, they require 81 square feet of mulch
Add 12.18 to both sides so you have 2.14x= 6.52, the you divide both sides by 2.14 so the answer is 6.52/2.14 which is 3.05 rounded