document.write( "Question 338556: The width of a rectangle is 4 cm less than its length. If the area of the rectangle is 87cm^2 what are the dimensions of the rectangle? Round to the nearest thousandth. \r
\n" ); document.write( "\n" ); document.write( "I have figured out the answer as \r
\n" ); document.write( "\n" ); document.write( "Length = 11.539
\n" ); document.write( "Width = 7.539\r
\n" ); document.write( "\n" ); document.write( "Just don't know the formula or how to solve, help would be greatly appreciated thank you.
\n" ); document.write( "

Algebra.Com's Answer #242704 by Alan3354(69443)\"\" \"About 
You can put this solution on YOUR website!
The width of a rectangle is 4 cm less than its length. If the area of the rectangle is 87cm^2 what are the dimensions of the rectangle? Round to the nearest thousandth.
\n" ); document.write( "I have figured out the answer as
\n" ); document.write( "Length = 11.539
\n" ); document.write( "Width = 7.539
\n" ); document.write( "--------------------
\n" ); document.write( "Area = L*W
\n" ); document.write( "L = W+4
\n" ); document.write( "Area = (W+4)*W = 87
\n" ); document.write( "W^2 + 4W = 87
\n" ); document.write( "W^2 + 4W - 87 = 0
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B4x%2B-87+=+0\") has the following solutons:
\n" ); document.write( "
\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
\n" ); document.write( "
\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
\n" ); document.write( "
\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%284%29%5E2-4%2A1%2A-87=364\".
\n" ); document.write( "
\n" ); document.write( " Discriminant d=364 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-4%2B-sqrt%28+364+%29%29%2F2%5Ca\".
\n" ); document.write( "
\n" ); document.write( " \"x%5B1%5D+=+%28-%284%29%2Bsqrt%28+364+%29%29%2F2%5C1+=+7.53939201416946\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%284%29-sqrt%28+364+%29%29%2F2%5C1+=+-11.5393920141695\"
\n" ); document.write( "
\n" ); document.write( " Quadratic expression \"1x%5E2%2B4x%2B-87\" can be factored:
\n" ); document.write( " \"1x%5E2%2B4x%2B-87+=+%28x-7.53939201416946%29%2A%28x--11.5393920141695%29\"
\n" ); document.write( " Again, the answer is: 7.53939201416946, -11.5393920141695.\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%2B4%2Ax%2B-87+%29\"

\n" ); document.write( "\n" ); document.write( "----------------
\n" ); document.write( "W = x (ignore the negative solution)
\n" ); document.write( "W = 7.53939 ...
\n" ); document.write( "L = 11.53939...
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