SOLUTION: The width of a garden is 8 feet less than the length. If the area of the garden is 20 square feet, find the length and the width. How do I write a polynominal for this then sol

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The width of a garden is 8 feet less than the length. If the area of the garden is 20 square feet, find the length and the width. How do I write a polynominal for this then sol      Log On


   



Question 344548: The width of a garden is 8 feet less than the length. If the area of the garden is 20 square feet, find the length and the width.
How do I write a polynominal for this then solve it?

Found 2 solutions by vleith, JBarnum:
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Let the lenght be L. Let the Wdith be W
AreaOfRectangle+=+Length+%2A+Width
You are told the area = 20 and that the width is length-8
So
20+=+L+%2A+W
20+=+L+%2A+%28L-8%29
20+=+L%5E2+-+8L
0+=+L%5E2+-8L+-+20
0+=+%28L-10%29%28L%2B2%29
So L is either 10 or -2. Since L cannot be negative, then L=10
Which makes W = 10-8 = 2

Answer by JBarnum(2146) About Me  (Show Source):
You can put this solution on YOUR website!
w=width
l=length
w=l-8
A=lw
A=20
20=l%28l-8%29
20=l%5E2-8l
0=l%5E2-8l-20
you should see that +2 and -10 add to get -8 and multiply to get -20
0=%28l%2B2%29%28l-10%29
l=10
the length cant be negative
w=l-8
w=10-8
w=2