document.write( "Question 889337: A rectangle is 72 sq.m and its perimeter is 34 m.find its length and breadth? \n" ); document.write( "
Algebra.Com's Answer #538092 by LinnW(1048)![]() ![]() You can put this solution on YOUR website! set W = width \n" ); document.write( "set L = length \n" ); document.write( "L*W = 72 \n" ); document.write( "2W + 2L = 34 \n" ); document.write( "add -2L to each side \n" ); document.write( "2W = 34 - 2L \n" ); document.write( "divide each side by 2 \n" ); document.write( " W = 17 - L \n" ); document.write( "substitute ( 17 - L ) for W in L*W = 72 \n" ); document.write( "L*( 17 - L ) = 72 \n" ); document.write( "17L - L^2 = 72 \n" ); document.write( "add -72 to each side \n" ); document.write( "17L - L^2 - 72 = 0 \n" ); document.write( "multiply each side by -1 \n" ); document.write( "L^2 - 17L + 72 = 0 \n" ); document.write( "(L - 8)(L - 9) = 0 \n" ); document.write( "So L = 8 or L = 9 \n" ); document.write( "Suppose L = 9 \n" ); document.write( "Substitute 9 for L in 2W + 2L = 34 \n" ); document.write( " 2W + 2(9) = 34 \n" ); document.write( " 2W + 18 = 34 \n" ); document.write( "add -18 to each side \n" ); document.write( " 2W = 16 \n" ); document.write( " W = 8 \n" ); document.write( "So length is 9 and width is 8 \n" ); document.write( " |