document.write( "Question 630170: The length of a rectangular flower bed is 11 feet less than 3 times its width. The area of the bed is 20 ft^2. Find the dimensions of the flower bed.\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #396755 by graphmatics(170)\"\" \"About 
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Let w be the width of the rectangle then the length is 3w-11. For the area we have that \"+%28w%29%283%2Aw-11%29=20+\". \"+3%2Aw%5E2-11%2Aw-20=0+\" \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"3x%5E2%2B-11x%2B-20+=+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=%28-11%29%5E2-4%2A3%2A-20=361\".
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\n" ); document.write( " Discriminant d=361 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--11%2B-sqrt%28+361+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%28-11%29%2Bsqrt%28+361+%29%29%2F2%5C3+=+5\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-11%29-sqrt%28+361+%29%29%2F2%5C3+=+-1.33333333333333\"
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\n" ); document.write( " Quadratic expression \"3x%5E2%2B-11x%2B-20\" can be factored:
\n" ); document.write( " \"3x%5E2%2B-11x%2B-20+=+3%28x-5%29%2A%28x--1.33333333333333%29\"
\n" ); document.write( " Again, the answer is: 5, -1.33333333333333.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+3%2Ax%5E2%2B-11%2Ax%2B-20+%29\"
\n" ); document.write( ". The width is 5 ft and the length is 3*5-11=4
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