document.write( "Question 686696: I am not understanding how to start this word problem. We are supposed to be using quadratic equations. The problem is.....
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document.write( " The length of a rectangle is 1cm more than twice it's width and 2cm less than the length of the diagonal of the rectangle. Find the dimensions of the rectangle.\r
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document.write( "I think the diagonal part is confusing me because we have never solved a problem with diagonal before. \n" );
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Algebra.Com's Answer #424890 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! The length of a rectangle is 1cm more than twice it's width and 2cm less than the length of the diagonal of the rectangle. \n" ); document.write( " Find the dimensions of the rectangle. \n" ); document.write( ": \n" ); document.write( "Let a = the width \n" ); document.write( "Let b = the length \n" ); document.write( "Let c = the diagonal \n" ); document.write( "; \n" ); document.write( "Write an equation for each statement, get each equation in terms of a: \n" ); document.write( "\"The length of a rectangle is 1cm more than twice it's width\" \n" ); document.write( "b = 2a + 1 \n" ); document.write( ": \n" ); document.write( "\"the length is 2cm less than the length of the diagonal of the rectangle.\" \n" ); document.write( "b = c - 2 \n" ); document.write( "replace b with (2a+1) \n" ); document.write( "2a + 1 = c - 2 \n" ); document.write( "2a + 1 + 2 = c \n" ); document.write( "c = 2a + 3 \n" ); document.write( ": \n" ); document.write( "The diagonal is the hypotenuse (c) of the rectangle where \n" ); document.write( "a^2 + b^2 = c^2 \n" ); document.write( "Replace b with (2a+1) and replace c with (2a+3) \n" ); document.write( "a^2 + (2a+1)^2 = (2a+3)^2 \n" ); document.write( "FOIL \n" ); document.write( "a^2 + 4a^2 + 2a + 2a + 1 = 4a^2 + 6a + 6a + 9 \n" ); document.write( "Which is \n" ); document.write( "5a^2 + 4a + 1 = 4a^2 + 12a + 9 \n" ); document.write( "Combine like terms on the left \n" ); document.write( "5a^2 - 4a^2 + 4a - 12a + 1 - 9 = 0 \n" ); document.write( "a^2 - 8a - 8 = 0 \n" ); document.write( "Solve this quadratic equation using the quadratic formula \n" ); document.write( " \n" ); document.write( "where x = a; b = -8; c = -8 \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "two solutions but we only need the positive solution which is approx \n" ); document.write( "a = \n" ); document.write( "a = \n" ); document.write( "a = 8.9 cm is the width \n" ); document.write( "then \n" ); document.write( "b = 2(8.9) + 1 \n" ); document.write( "b = 18.8 cm is the length \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check this by finding the hypotenuse \n" ); document.write( "c = 2(8.9) + 3 \n" ); document.write( "c = 20.8 \n" ); document.write( ": \n" ); document.write( "Enter into calc \n" ); document.write( ": \n" ); document.write( " Find the dimensions of the rectangle. 18.8 by 8.9 \n" ); document.write( " |