Respuesta :

(6+2w)*w=36
 6w+2w^2=36
 2w^2+6w-36=0
2(w^2+3w-18)=0
 2(w+6)(w-3)=0
 w=3 or w=-6

width cannot be negative thus it must be 3 if the width is 3 then
36=3l
 36/3=l
 12=l

Hope this helps

Answer:

The length is 12 feet and width is 3 feet of the wall of the barn.

Step-by-step explanation:

Given : The area of a rectangular wall of a barn is 36 square feet. Its length is 6 feet longer than twice its width.

To Find : The length and width of the wall of the barn ?

Solution :

Let the width of the wall is 'w'.

Its length is 6 feet longer than twice its width.

The length of the wall is l=6+2w

The area of the wall is 36 square feet.

The area of the rectangular wall is [tex]A=l\times w[/tex]

[tex]36=(6+2w)\times w[/tex]

[tex]36=6w+2w^2[/tex]

[tex]w^2+3w-18=0[/tex]

Apply middle term split,

[tex]w^2+6w-3w-18=0[/tex]

[tex]w(w+6)-3(w+6)=0[/tex]

[tex](w+6)(w-3)=0[/tex]

[tex]w=-6,3[/tex]

Reject w=-6

The width of the wall is w=3 feet.

The length of the wall is l=6+2(3)=6+6=12

Therefore, The length is 12 feet and width is 3 feet of the wall of the barn.