document.write( "Question 694149: the rectangular air filter 4 inches less than twice the width Find the length and width of the filter with with a area of 336 square inches
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Algebra.Com's Answer #427752 by mananth(16946) $\"\"$ $\"About$

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Area = Length * width\r
\n" ); document.write( "\n" ); document.write( "let length be l
\n" ); document.write( "and width be w\r
\n" ); document.write( "\n" ); document.write( "w= 2l-4\r
\n" ); document.write( "\n" ); document.write( "So l(2l-4)=336\r
\n" ); document.write( "\n" ); document.write( "2l^2-4l=336
\n" ); document.write( "/2
\n" ); document.write( "l^2-2l=168\r
\n" ); document.write( "\n" ); document.write( "l^2-2l-168=0
\n" ); document.write( "l^2-14l+12l-168=0\r
\n" ); document.write( "\n" ); document.write( "l(l-14)+12(l-14)=0\r
\n" ); document.write( "\n" ); document.write( "(l-14)(l+12)=0\r
\n" ); document.write( "\n" ); document.write( "l=14 or l=-12\r
\n" ); document.write( "\n" ); document.write( "length cannot be negative
\n" ); document.write( "so
\n" ); document.write( "l=14\r
\n" ); document.write( "\n" ); document.write( "width = 336/14
\n" ); document.write( "=24\r
\n" ); document.write( "\n" ); document.write( "l= 14 inches
\n" ); document.write( "width = 24\r
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