document.write( "Question 75657: If the perimeter of a rectangle is 18ft and the width is 5ft, find its length. \n" ); document.write( "
Algebra.Com's Answer #54341 by jim_thompson5910(35256)\"\" \"About 
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The perimeter of a rectangle is the width+length+width+length. Since the 2 width's are the same we can say w+w=2w. The same thing applies for the length: L+L=2L. So the perimeter formula can be written as:\r
\n" ); document.write( "\n" ); document.write( "\"P=2w%2B2L\" where P is the perimeter
\n" ); document.write( "\"18=2%285%29%2B2L\" Now plug in the given perimeter and the width to find the length
\n" ); document.write( "\"18=10%2B2L\"
\n" ); document.write( "\"18-10=cross%2810-10%29%2B2L\" Subtract 10 from both sides
\n" ); document.write( "\"8=2L\"
\n" ); document.write( "\"8%2F2=cross%282%2F2%29L\" Divide both sides by 2
\n" ); document.write( "\"L=4\"
\n" ); document.write( "So the length is 4 feet
\n" ); document.write( "


\n" ); document.write( "Check:
\n" ); document.write( "\"18=2%285%29%2B2%284%29\"
\n" ); document.write( "\"18=10%2B8\"
\n" ); document.write( "\"18=18\" works \n" ); document.write( "

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