SOLUTION: The width of a rectangle is 4 feet less than the length. The area is 320ft^2. Find the width of the rectangle. ___feet Thank you

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The width of a rectangle is 4 feet less than the length. The area is 320ft^2. Find the width of the rectangle. ___feet Thank you      Log On


   

Question 41042: The width of a rectangle is 4 feet less than the length. The area is 320ft^2. Find the width of the rectangle.
___feet
Thank you
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
Width(w) = l - 4
Length(l) = l
Length * Width = Area
(l)(l - 4) = 320
l^2 - 4l - 320 = 0
(l - 20)(l + 16) = 0
l+=+20 or l+=+-16
Since your length can not be negative, your length is: l+=+20
Plug:
Width = l - 4
Width = 20 - 4
Width = 16