SOLUTION: the perimeter of a rectangle is 84 feet. the length of the rectangle is 3 feet less than 2 times its width. what is the length of the rectangle

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Question 697873: the perimeter of a rectangle is 84 feet. the length of the rectangle is 3 feet less than 2 times its width. what is the length of the rectangle
Answer by Stitch(470) About Me  (Show Source):
You can put this solution on YOUR website!
Set-Up
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L = length
W = width
Equation 1: 84+=+2L+%2B+2W
Equation 2: L+=+2W+-+3
Solution:
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Plug (2W - 3) into equation 1 for L
Equation 1: 84+=+2L+%2B+2W
84+=+2%2A%282W+-+3%29+%2B+2W
Simplify
84+=+4W+-+6+%2B+2W
Simplify
84+=+6W+-+6
Add 6 to both sides
90+=+6W
Divide both sides by 6
highlight%2815+=+W%29
Now plug 15 into equation 2 for W
Equation 2: L+=+2W+-+3
L+=+2%2A%2815%29+-+3
L+=+30+-+3
highlight_green%28L+=+27%29