document.write( "Question 223710: what is the length of a rectangle is twice its width if the width is increased by one meter and the length is diminished by three meters the area will be 12 square meters \n" ); document.write( "
Algebra.Com's Answer #167206 by drj(1380)\"\" \"About 
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What is the length of a rectangle is twice its width if the width is increased by one meter and the length is diminished by three meters the area will be 12 square meters.\r
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\n" ); document.write( "\n" ); document.write( "Step 1. Let w be the width\r
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\n" ); document.write( "\n" ); document.write( "Step 2. Let 2w be the length.\r
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\n" ); document.write( "\n" ); document.write( "Step 3. Let w+1 be the width increased by one meter.\r
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\n" ); document.write( "\n" ); document.write( "Step 4. Let 2w-3 be the length diminished by three meters.\r
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\n" ); document.write( "\n" ); document.write( "Step 5. The Area A=(w+1)(2w-3)=12 since the area will be 12 meters with these changed dimensions.\r
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\n" ); document.write( "\n" ); document.write( "Step 6. Solving the equation in Step 5 will lead to a quadratic equation as follows:\r
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\n" ); document.write( "\n" ); document.write( "\"2w%5E2-3w%2B2w-3=12\"\r
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\n" ); document.write( "\n" ); document.write( "Subtract 12 from both sides of the equation\r
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\n" ); document.write( "\n" ); document.write( "\"2w%5E2-w-3-12=12-12\"\r
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\n" ); document.write( "\n" ); document.write( "\"2w%5E2-w-15=0\"\r
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\n" ); document.write( "\n" ); document.write( "Step 7. To solve, use the quadratic formula given as \"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\" \r
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\n" ); document.write( "\n" ); document.write( "where a=2, b=-1, and c=-15.\r
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"2x%5E2%2B-1x%2B-15+=+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=%28-1%29%5E2-4%2A2%2A-15=121\".
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\n" ); document.write( " Discriminant d=121 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--1%2B-sqrt%28+121+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%28-1%29%2Bsqrt%28+121+%29%29%2F2%5C2+=+3\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-1%29-sqrt%28+121+%29%29%2F2%5C2+=+-2.5\"
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\n" ); document.write( " Quadratic expression \"2x%5E2%2B-1x%2B-15\" can be factored:
\n" ); document.write( " \"2x%5E2%2B-1x%2B-15+=+2%28x-3%29%2A%28x--2.5%29\"
\n" ); document.write( " Again, the answer is: 3, -2.5.\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-1%2Ax%2B-15+%29\"

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\n" ); document.write( "\n" ); document.write( "Selecting the positive solution given as \"w=3\", then \"2w=6\". Check area A with width 3+1=4 and length 2w-3=3. So the area with these dimensions is 12 as given by the problem statement.\r
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\n" ); document.write( "\n" ); document.write( "Step 8. ANSWER: The length is 6 meters.\r
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\n" ); document.write( "\n" ); document.write( "I hope the above steps were helpful.\r
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\n" ); document.write( "\n" ); document.write( "For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.\r
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\n" ); document.write( "\n" ); document.write( "Good luck in your studies!\r
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\n" ); document.write( "\n" ); document.write( "Respectfully,
\n" ); document.write( "Dr J
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