document.write( "Question 941014: The Johnson family is building a dog house. The total floor surface area will be 24 sq. ft. If the length is 6 more than three times the width what is the width of the dog house? I am very lost how do I get the width? \n" ); document.write( "
Algebra.Com's Answer #573560 by macston(5194)\"\" \"About 
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The floor area is 24 sq ft
\n" ); document.write( "Thus L x W = 24 sq ft
\n" ); document.write( "The length is 6 more then 3 times the width
\n" ); document.write( "L=3W+6 Substitute second equation in first for L
\n" ); document.write( "(3W+6) x W=24
\n" ); document.write( "\"3w%5E2+%2B+6W=24\" Divide through by 3
\n" ); document.write( "\"%283W%5E2%2B6W%29%2F3=24%2F3\"
\n" ); document.write( "\"W%5E2%2B2W=8\" subtract 8 from each side
\n" ); document.write( "\"W%5E2%2B2W-8=8-8\"
\n" ); document.write( "\"w%5E2%2B2W-8=0\"
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"aW%5E2%2BbW%2Bc=0\" (in our case \"1W%5E2%2B2W%2B-8+=+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=%282%29%5E2-4%2A1%2A-8=36\".
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\n" ); document.write( " Discriminant d=36 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-2%2B-sqrt%28+36+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"W%5B1%5D+=+%28-%282%29%2Bsqrt%28+36+%29%29%2F2%5C1+=+2\"
\n" ); document.write( " \"W%5B2%5D+=+%28-%282%29-sqrt%28+36+%29%29%2F2%5C1+=+-4\"
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\n" ); document.write( " Quadratic expression \"1W%5E2%2B2W%2B-8\" can be factored:
\n" ); document.write( " \"1W%5E2%2B2W%2B-8+=+1%28W-2%29%2A%28W--4%29\"
\n" ); document.write( " Again, the answer is: 2, -4.\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%2B2%2Ax%2B-8+%29\"

\n" ); document.write( "\n" ); document.write( "So W=2 or -4
\n" ); document.write( "For an actual measurement only the 2 makes sense
\n" ); document.write( "So W=2 feet L=3W+6=3(2)+6=6+6=12 feet
\n" ); document.write( "CHECK:
\n" ); document.write( "The area is 24 sq ft
\n" ); document.write( "A=L x W
\n" ); document.write( "24 sq ft=12 ft x 2 ft
\n" ); document.write( "24 sq ft=24 sq ft
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