Patricia D. answered 03/16/19
P.A.T.T.I. - P.atiently A.nd T.enderly T.utoring I.ndividuals
The length of a rectangle is 8 feet more than the width. If the width is increased by 4 feet, and the length is decreased by 5 feet, the area remains the same. Find the dimensions of the original rectangle.
If L = length and W = width
First rectangle
L = w + 8
Second rectangle
W =W + 4 L = (w + 8) - 5 = w + 3
If the areas are the same, A1 = A 2 amd this gives us
(w + 8)w = (w + 4) (w + 3)
w2 + 8w = w2 + 7w +12 subtract w2 from both sides
8w = 7w + 12 subtract 7w
w = 12
original rectangle is 20 x 12
Patti D.