Question

The area of a bulletin board is 55 ft2. The length is nine feet less than four times the width. Find the length and the width, in feet, of the bulletin board.

Answer 1

The length and width are 11ft and 5ft respectively

Explanation:

let the

length = L

Width = W

Area = LW = 55

The length is nine feet less than four times the width

L = 4W - 9

W (4W - 9) = 55

4W^2 - 9W -55 = 0

4W^2 - 20W + 11W - 55 = 0

4W(W - 5) + 11(W - 5) = 0

(W - 5)(4W + 11) = 0

W - 5 = 0 , 4W + 11=0

W = 5 or - 11/4

since the width cannot be negative, W = 5

LW = 55

L = 55/5

L = 11

The length and width are 11ft and 5ft respectively.