document.write( "Question 953749: The area of a rectangular field is 428 square meters and the width is 10m less than the length. What is the size of the width? \n" ); document.write( "
Algebra.Com's Answer #582569 by macston(5194)\"\" \"About 
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L=length; W=width=L-10m; A=area=L*W
\n" ); document.write( "\"A=L%2AW\"
\n" ); document.write( "\"428m%5E2+=L%2AW\" Substitute for W
\n" ); document.write( "\"428m%5E2=L%2A%28L-10m%29\"
\n" ); document.write( "\"428m%5E2=L%5E2-10L\" Subtract 428m^2 from each side
\n" ); document.write( "\"0=L%5E2-10L-428m%5E2\"\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"aL%5E2%2BbL%2Bc=0\" (in our case \"1L%5E2%2B-10L%2B-428+=+0\") has the following solutons:
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\n" ); document.write( " \"L%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=%28-10%29%5E2-4%2A1%2A-428=1812\".
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\n" ); document.write( " Discriminant d=1812 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--10%2B-sqrt%28+1812+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"L%5B1%5D+=+%28-%28-10%29%2Bsqrt%28+1812+%29%29%2F2%5C1+=+26.2837966537928\"
\n" ); document.write( " \"L%5B2%5D+=+%28-%28-10%29-sqrt%28+1812+%29%29%2F2%5C1+=+-16.2837966537928\"
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\n" ); document.write( " Quadratic expression \"1L%5E2%2B-10L%2B-428\" can be factored:
\n" ); document.write( " \"1L%5E2%2B-10L%2B-428+=+1%28L-26.2837966537928%29%2A%28L--16.2837966537928%29\"
\n" ); document.write( " Again, the answer is: 26.2837966537928, -16.2837966537928.\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-10%2Ax%2B-428+%29\"

\n" ); document.write( "\n" ); document.write( "\"L=26.28\" The length is 26.28 meters.
\n" ); document.write( "\"W=L-10m=26.28m-10m=16.28m\" ANSWER: The width is 16.28 meters.
\n" ); document.write( "CHECK:
\n" ); document.write( "\"L%2AW=A\"
\n" ); document.write( "\"26.28m%2816.28m%29=428m%5E2\"
\n" ); document.write( "\"427.84m=428m\" Discrepancy from rounding.
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