Question 5142: please help
The length of a rectangle is 4 centimeters less than twice the width. Find the dimensions of the rectangle if the area is 96 square centimeters.
Answer by guapa(62)   (Show Source):
You can put this solution on YOUR website! You need the area formula for a rectangle. A = lw
We have the value for the area which is 96
The length is 4cm less than twice the width. Let w = width then l=2w-4
Now we can substitue into the formula:
96=(2w-4)w
96=2w²-4w
2w²-4w-96=0
2w²-16w+12w-96=0
2w(w-8)+12(w-8)=0
(2w+12)(w-8)=0
2w+12=0, w= -12/2= -6
w-8=0, w=8
Since we are looking for dimensions of a rectangle we can disgard the negative solution.
w=8 and 2w-4=l , 2(8)-4=l, 12=l
The dimension for the rectangle is 12 by 8 cm.
Check it A=l*w = 12*8=96
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