document.write( "Question 692302: the length of a rectangle is five feet less than twice the width. its area is 375 square feet. Find its dimensions. I need to know how to work it out.. Or just a equation \n" ); document.write( "
Algebra.Com's Answer #426960 by Stitch(470)\"\" \"About 
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Set-Up
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\n" ); document.write( "A = L * W (Area of a rectangle)
\n" ); document.write( "Given: A = 375, L = 2W - 5
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\n" ); document.write( "Solution:
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\n" ); document.write( "Substitute the given information into the equation for the area of a rectangle
\n" ); document.write( "\"%28375%29+=+%282W+-+5%29+%2A+W\" Simplify
\n" ); document.write( "\"375+=+2W%5E2+-+5W\" Subtract 128 from both sides
\n" ); document.write( "\"0+=+2W%5E2+-+5W+-+375\"
\n" ); document.write( "Use the quadratic equation\r
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"aW%5E2%2BbW%2Bc=0\" (in our case \"2W%5E2%2B-5W%2B-375+=+0\") has the following solutons:
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\n" ); document.write( " \"W%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%28-5%29%5E2-4%2A2%2A-375=3025\".
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\n" ); document.write( " Discriminant d=3025 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--5%2B-sqrt%28+3025+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"W%5B1%5D+=+%28-%28-5%29%2Bsqrt%28+3025+%29%29%2F2%5C2+=+15\"
\n" ); document.write( " \"W%5B2%5D+=+%28-%28-5%29-sqrt%28+3025+%29%29%2F2%5C2+=+-12.5\"
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\n" ); document.write( " Quadratic expression \"2W%5E2%2B-5W%2B-375\" can be factored:
\n" ); document.write( " \"2W%5E2%2B-5W%2B-375+=+2%28W-15%29%2A%28W--12.5%29\"
\n" ); document.write( " Again, the answer is: 15, -12.5.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B-5%2Ax%2B-375+%29\"

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\n" ); document.write( "\n" ); document.write( "The answers were W = 15feet or -12.5feet. but since you can not have a negative width. Just use the 15\r
\n" ); document.write( "\n" ); document.write( "Now we can find the length
\n" ); document.write( "L = 2W - 5
\n" ); document.write( "Plug 15 in for W
\n" ); document.write( "\"L+=+2%2A%2815%29+-%285%29\"
\n" ); document.write( "\"L+=+30+-+5\"
\n" ); document.write( "\"highlight_green%28L+=+25+feet%29\"\r
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