document.write( "Question 1204421: Cynthia Besch wants to buy a rug for a room that is 27ft wide and 35ft long. She wants to leave a uniform strip of floor around the rug. She can afford to buy 609 square feet of carpeting. What dimensions should the rug​ have? \n" ); document.write( "
Algebra.Com's Answer #840651 by math_tutor2020(3817)\"\" \"About 
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\n" ); document.write( "A question like this has been asked before.\r
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\n" ); document.write( "\n" ); document.write( "Review this link to see an example how to solve.
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/Quadratic_Equations.faq.question.1197474.html\r
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\n" ); document.write( "\n" ); document.write( "If you are still stuck, then read on.\r
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\n" ); document.write( "\n" ); document.write( "Draw out a diagram as indicated in the link above.\r
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\n" ); document.write( "\n" ); document.write( "There will be a large rectangle that is 27 feet by 35 feet.
\n" ); document.write( "This represents the dimensions of the room.\r
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\n" ); document.write( "\n" ); document.write( "Inside that larger rectangle will be a smaller rectangle with dimensions (27-2x) feet by (35-2x) feet.
\n" ); document.write( "x represents the width of the uniform strip.
\n" ); document.write( "This is the buffer gap between the edge of the rug to the edge of the wall.\r
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\n" ); document.write( "\n" ); document.write( "The area of the smaller rectangle is (27-2x)(35-2x).
\n" ); document.write( "Set this equal to 609 because this is the amount of carpet she can buy.\r
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\n" ); document.write( "\n" ); document.write( "(27-2x)(35-2x) = 609
\n" ); document.write( "27(35-2x)-2x(35-2x) = 609
\n" ); document.write( "945-54x-70x+4x^2 = 609
\n" ); document.write( "945-54x-70x+4x^2 - 609 = 0
\n" ); document.write( "4x^2 - 124x + 336 = 0
\n" ); document.write( "4(x^2 - 31x + 84) = 0
\n" ); document.write( "x^2 - 31x + 84 = 0\r
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\n" ); document.write( "\n" ); document.write( "We could factor, but I think the quadratic formula is the most efficient pathway.
\n" ); document.write( "This is because we don't have to worry about guess-and-check.\r
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\n" ); document.write( "\n" ); document.write( "Plug a = 1, b = -31, c = 84 into the quadratic formula below.
\n" ); document.write( "\"x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-31%29%2B-sqrt%28%28-31%29%5E2-4%281%29%2884%29%29%29%2F%282%281%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2831%2B-sqrt%28961+-+336%29%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2831%2B-sqrt%28625%29%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2831%2B-++25%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2831%2B25%29%2F%282%29\" or \"x+=+%2831-25%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2856%29%2F%282%29\" or \"x+=+%286%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+28\" or \"x+=+3\"\r
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\n" ); document.write( "\n" ); document.write( "If x = 28, then 27-2x = 27-2*28 = -29, which is not valid.
\n" ); document.write( "The side length must be positive.\r
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\n" ); document.write( "\n" ); document.write( "If x = 3, then,
\n" ); document.write( "27-2x = 27-2*3 = 21
\n" ); document.write( "and
\n" ); document.write( "35-2x = 35-2*3 = 29
\n" ); document.write( "Both results are positive.
\n" ); document.write( "Therefore x = 3 is valid and practical.
\n" ); document.write( "A gap of 3 feet produces a rug that is 21 feet by 29 feet.\r
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\n" ); document.write( "\n" ); document.write( "As a check, 21*29 = 609, and we have confirmed the answer is correct.\r
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\n" ); document.write( "\n" ); document.write( "Answer: The rug should be 21 feet by 29 feet.
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