document.write( "Question 1027714: A rectangular countertop has an area of 27 square feet. Its perimeter is 24 feet. What are the dimensions of the counter?\r
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Algebra.Com's Answer #643017 by Cromlix(4381)![]() ![]() You can put this solution on YOUR website! Hi there, \n" ); document.write( "A rectangular countertop \n" ); document.write( "has an area of 27 square feet. \n" ); document.write( "Area = length x breadth \n" ); document.write( "xy = 27.......(1) \n" ); document.write( "x = 27/y.......(1) \n" ); document.write( "Its perimeter is 24 feet. \n" ); document.write( "Perimeter = 2 x width + 2 x length \n" ); document.write( "24 = 2x + 2y \n" ); document.write( "2x + 2y = 24.......(2) \n" ); document.write( "Substitute x = 27/y into Eq(2) \n" ); document.write( "2(27/y) + 2y = 24 \n" ); document.write( "54/y + 2y = 24 \n" ); document.write( "Multiply through by y \n" ); document.write( "54 + 2y^2 = 24y \n" ); document.write( "Sort into ax^2 + bx + c form \n" ); document.write( "2y^2 - 24y + 54 \n" ); document.write( "Divide by 2 \n" ); document.write( "2(y^2 - 12y + 27)= 0 \n" ); document.write( "2(y - 3)(y - 9) = 0 \n" ); document.write( "y - 3 = 0 \n" ); document.write( "y = 3 \n" ); document.write( "y - 9 = 0 \n" ); document.write( "y = 9 \n" ); document.write( "By substituting either y = 3 \n" ); document.write( "back into Eq(1) \n" ); document.write( "x = 27/y \n" ); document.write( "x = 27/3 \n" ); document.write( "x = 9 \n" ); document.write( "or Substituting y = 9 \n" ); document.write( "back into Eq(1) \n" ); document.write( "x = 27/y \n" ); document.write( "x = 27/9 \n" ); document.write( "x = 3 \n" ); document.write( "So, either your breadth is 3ft \n" ); document.write( "and the length is 9ft \n" ); document.write( "or \n" ); document.write( "breadth is 9ft \n" ); document.write( "and the length is 3ft \n" ); document.write( "Hope this helps :-) \n" ); document.write( " |