document.write( "Question 283642: The length of a rectangle is 3cm more than 2 times its width. If the area of the rectangle is 93cm^2, find the dimensions of the rectangle. Enter your answers in the blanks. Enter only the numeric values rounded to the nearest thousandth of centimeter Width=________cm, Length=_____________cm. \n" ); document.write( "
Algebra.Com's Answer #205843 by oberobic(2304)\"\" \"About 
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L = length
\n" ); document.write( "W = width
\n" ); document.write( "A = area
\n" ); document.write( "A = L*W
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\n" ); document.write( "L = 2W + 3
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\n" ); document.write( "A = 93 cm^2
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\n" ); document.write( "Substitute L = 2W+3 in the area equation to solve.
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\n" ); document.write( "L*W = 93 cm^2
\n" ); document.write( "(2W +3) * W = 93
\n" ); document.write( "2W^2 + 3W = 93
\n" ); document.write( "2W^2 + 3W -93 = 0
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\n" ); document.write( "This does not factor nicely, so you need to use the quadratic equation.
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"aW%5E2%2BbW%2Bc=0\" (in our case \"2W%5E2%2B3W%2B-93+=+0\") has the following solutons:
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\n" ); document.write( " \"W%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=%283%29%5E2-4%2A2%2A-93=753\".
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\n" ); document.write( " Discriminant d=753 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-3%2B-sqrt%28+753+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"W%5B1%5D+=+%28-%283%29%2Bsqrt%28+753+%29%29%2F2%5C2+=+6.11021136700612\"
\n" ); document.write( " \"W%5B2%5D+=+%28-%283%29-sqrt%28+753+%29%29%2F2%5C2+=+-7.61021136700612\"
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\n" ); document.write( " Quadratic expression \"2W%5E2%2B3W%2B-93\" can be factored:
\n" ); document.write( " \"2W%5E2%2B3W%2B-93+=+2%28W-6.11021136700612%29%2A%28W--7.61021136700612%29\"
\n" ); document.write( " Again, the answer is: 6.11021136700612, -7.61021136700612.\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%2B3%2Ax%2B-93+%29\"

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\n" ); document.write( "This provides two solutions: W=6.11 and W=-7.61.
\n" ); document.write( "W cannot be negative, so the approximate value is W=6.11.
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\n" ); document.write( "Substituting, W=6.11, we can find L.
\n" ); document.write( "L = 93/6.11
\n" ); document.write( "L = 15.22 cm
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\n" ); document.write( "Checking, does the area = 93 cm^2?
\n" ); document.write( "(15.22)(6.11) = 92.9942 cm^2, which is close enough to 93.
\n" ); document.write( "Correct.
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\n" ); document.write( "Checking, does L = 2W + 3?
\n" ); document.write( "2W = 2*6.11 = 12.22 cm
\n" ); document.write( "12.22 + 3 = 15.22 cm
\n" ); document.write( "Correct.
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\n" ); document.write( "Answer:
\n" ); document.write( "L = 15.22 cm
\n" ); document.write( "W = 6.11 cm
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\n" ); document.write( "Done.
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