Respuesta :

Answer: The length is 15 feet.

Step-by-step explanation:

  • L = 3w - 3 (length is 3 feet less than three times the width)
  • 21 = w + (3w -3)
  • 21 = 4w - 3 (add like terms)
  • 24 = 4w (substract 3 from both sides)
  • 6 = w <-- width

But, the problem is asking for the length...

  • L = 3w - 3
  • L = 3(6) - 3
  • L = 18 - 3
  • L = 15 ft