square feet 6

Question

The area of a rectangular wall of a barn is
42
square feet. Its length is
8
feet longer than twice its width. Find the length and width of the wall of the barn.

Answer 1

A=lw

w=width

2w+8=length

42=(2w+8)(w)

42=2w^2+8w

2w^2+8w-42=0

w^2+4w-21=0

(w+7)(w-3)=0

w-3=0

w=3 feet

l=2*3+8=14 feet