document.write( "Question 114473: the perimeter of a rectangle is 240cm . if the lenght is decreased .if the lenght is decreased by 10% and its breadth is increased by 20% we get the same perimeter. find the lenght and breadth of the rectangle \n" ); document.write( "
Algebra.Com's Answer #83489 by ankor@dixie-net.com(22740)\"\" \"About 
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The perimeter of a rectangle is 240cm. If the length is decreased by 10% and it's breadth is increased by 20%, we get the same perimeter. Find the length and breadth of the rectangle.
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\n" ); document.write( "Convert the new dimensions to: .9L and 1.2W
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\n" ); document.write( "2L + 2W = 240
\n" ); document.write( "Simplify, divide by 2:
\n" ); document.write( "L + W = 120
\n" ); document.write( "L = 120-W; use for substitution
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\n" ); document.write( "New dimensions
\n" ); document.write( "2(.9L) + 2(1.2W) = 240
\n" ); document.write( "Simplify divide by 2:
\n" ); document.write( ".9L + 1.2W = 120
\n" ); document.write( ":
\n" ); document.write( "Substitute (120-W) in the above equation:
\n" ); document.write( ".9(120-W) + 1.2W = 120
\n" ); document.write( "108 - .9W + 1.2W = 120
\n" ); document.write( ".3W = 120 - 108
\n" ); document.write( ".3W = 12
\n" ); document.write( "W = 12/.3
\n" ); document.write( "W = 40
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\n" ); document.write( "Find L
\n" ); document.write( "L = 120 - 40
\n" ); document.write( "L = 80
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\n" ); document.write( "Check solution:
\n" ); document.write( "2(80) + 2(40) = 240
\n" ); document.write( "and
\n" ); document.write( "2(.9*80) + 2(1.2*40) =
\n" ); document.write( "144 + 96 = 240 \n" ); document.write( "
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