document.write( "Question 405238: A square plywood platform has a perimeter which is 7 times the length of a side,decreased by 18. What is the length of a side? \n" ); document.write( "
Algebra.Com's Answer #286258 by MathLover1(20850)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "A square plywood platform has a \"perimeter\" which is \"7\" times the length of a side \"a\",decreased by \"18\".\r
\n" ); document.write( "\n" ); document.write( "\"perimeter=P\"\r
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\n" ); document.write( "\n" ); document.write( "\"P=4a\"\r
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\n" ); document.write( "\n" ); document.write( "\"4a=7a-18\"\r
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\n" ); document.write( "\n" ); document.write( "\"18=7a-4a\"\r
\n" ); document.write( "\n" ); document.write( "\"18=3a\"\r
\n" ); document.write( "\n" ); document.write( "\"18%2F3=a\"\r
\n" ); document.write( "\n" ); document.write( "\"a=6\"
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