Question

A sheet of metal is 9 inches longer than it is wide, and its total area is 252 square inches. Find the dimensions of the sheet of metal.
If w represents the width of the metal sheet, which of the following equations is a model for the given word problem?


A.
(3, –7)
B.
(–2, 7) and (3, –3)
C.
(3, 3)
D.
(2, 7) and (3, 9)

Answer 1

(9+w)w=252 or w(w+9)=252.
The quadratic equation applies: w²+9w-252=0=(w+21)(w-12), so w=12, because a negative zero is meaningless.
So the dimensions are width=12 in and length=21 in.