document.write( "Question 171632: A rope 100 feet long is stretched around four posts set at the corners of a rectangle whose area is 576 square feet. Find the dimensions of the rectangle. \n" ); document.write( "
Algebra.Com's Answer #126773 by Alan3354(69443)\"\" \"About 
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A rope 100 feet long is stretched around four posts set at the corners of a rectangle whose area is 576 square feet. Find the dimensions of the rectangle.
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\n" ); document.write( "Perimeter = 2L + 2W = 100
\n" ); document.write( "Area = L*W = 576
\n" ); document.write( "2L + 2W = 100
\n" ); document.write( "L+W = 50
\n" ); document.write( "L = 50-W
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\n" ); document.write( "A = L*W = (50-W)*W
\n" ); document.write( "576 = 50W - W^2
\n" ); document.write( "W^2 - 50W + 576 = 0
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Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B-50x%2B576+=+0\") has the following solutons:
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\n" ); document.write( " \"x%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=%28-50%29%5E2-4%2A1%2A576=196\".
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\n" ); document.write( " Discriminant d=196 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--50%2B-sqrt%28+196+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%28-50%29%2Bsqrt%28+196+%29%29%2F2%5C1+=+32\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-50%29-sqrt%28+196+%29%29%2F2%5C1+=+18\"
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\n" ); document.write( " Quadratic expression \"1x%5E2%2B-50x%2B576\" can be factored:
\n" ); document.write( " \"1x%5E2%2B-50x%2B576+=+%28x-32%29%2A%28x-18%29\"
\n" ); document.write( " Again, the answer is: 32, 18.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-50%2Ax%2B576+%29\"

\n" ); document.write( "\n" ); document.write( "W = 18, L = 32\r
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