The area of a rectangular wall of a barn is 20 square feet. Its length is 8 feet longer than the width. Find the length and width of the wall of the barn.

Question

I am not able to solve this. I have tried 4 times now.

Answer 1

20 = ( w + 8) w

 

20 = w^2 + 8w

 

0 = w^2 + 8x - 20

 

0 = ( w  +   10   )( w   -      2   )

 

 w + 10 = 0 ---> w = -10  ---> width cannot be negative; disqualified/rejected  

 

  w - 2= 0 ---> w = 2

 

Width is 2, length is 2+8=10

 

 

 

Answer 2

Let w = the width

Let w + 8 = the length

A = lw

20 = w(w+8)

20 = w² + 8w

w² + 8w - 20 = 0

(w+10)(w-2) = 0

w + 10 = 0    or   w - 2 = 0

     w = -10    or         w = 2 feet       A negative answer is illogical.

length = w + 8 = 2 + 8

length = 10 feet