The area of a rectangle wall of a barn is 320 square feet. it s length is12 feet

Length = 32 feet

Width = 10 feet

Step-by-step explanation:

The area of a rectangle = length (L) x width (W)

The relationship between the length and width is that

L = 12 + 2W (i)

therefore

Area = L x W can be rewritten as (12 + 2W) x W

320 =  (12 + 2W) x W

320 = 12W + 2W^2

this can then be turned into a quadratic equation:

2W^2 + 12W - 320 = 0

Divide through by 2

W^2 + 6W - 160 = 0

W^2 - 10W + 16W - 160 = 0

W(W- 10) + 16(W- 10) = 0

(W- 10)(W + 16) = 0

hence W = -16 and 10

since width cannot be a negative value,

Width = 10

hence substituting for width = 10 into equation (i)

L = 12 + 2(10)

L = 12 +20 = 32

It's A.

Step-by-step explanation:

The line is drawn through the data, which means it has a positive slope.