document.write( "Question 1209654: Find the unique pair of real numbers (x,y) satisfying
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document.write( "(6x^2 - 18x + 17) + (3y^2 + 6y + 11) = 28
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document.write( "and x + y = 20.\r
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document.write( "Enter your answer as an ordered pair in the format $(x,y)$, where $x$ and $y$ are replaced by appropriate numbers. \n" );
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Algebra.Com's Answer #849780 by ikleyn(52786)![]() ![]() You can put this solution on YOUR website! . \n" ); document.write( "Find the unique pair of real numbers (x,y) satisfying \n" ); document.write( "(6x^2 - 18x + 17) + (3y^2 + 6y + 11) = 28 \n" ); document.write( "and x + y = 20. \n" ); document.write( "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " In the post by @CPhill, the final answer is {(8,12)}.\r \n" ); document.write( "\n" ); document.write( " This answer CONTRADICTS to what is written in his post before it, and is factually INCORRECT.\r \n" ); document.write( "\n" ); document.write( " Also, his post is full of non-necessary calculations.\r \n" ); document.write( "\n" ); document.write( " Below I present my solution, which is much shorter, simple and straightforward.\r \n" ); document.write( "\n" ); document.write( " At the end, I will provide a correct answer.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( "Starting equation is\r\n" ); document.write( "\r\n" ); document.write( " (6x^2 - 18x + 17) + (3y^2 + 6y + 11) = 28.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Simplify by combining like terms\r\n" ); document.write( "\r\n" ); document.write( " 6x^2 - 18x + 3y^2 + 6y = 28 - 17 - 11,\r\n" ); document.write( "\r\n" ); document.write( " 6x^2 - 18x + 3y^2 + 6y = 0.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Now divide both sides by 3\r\n" ); document.write( "\r\n" ); document.write( " 2x^2 - 6x + y^2 + 2y = 0.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Substitute here y = 20-x from the second given equation\r\n" ); document.write( "\r\n" ); document.write( " 2x^2 - 6x + (20-x)^2 + 2*(20-x) = 0,\r\n" ); document.write( "\r\n" ); document.write( " 2x^2 - 6x + 400 - 40x + x^2 + 40 - 2x = 0,\r\n" ); document.write( "\r\n" ); document.write( " 3x^2 - 48x + 440 = 0.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "The discriminant of this quadratic equation is negative\r\n" ); document.write( "\r\n" ); document.write( " d = b^2 - 4ac = (-48)^2 - 4*3*440 = -2976,\r\n" ); document.write( "\r\n" ); document.write( "which means that equation (2) has no solution.\r\n" ); document.write( "\r \n" ); document.write( "\n" ); document.write( "ANSWER. There is \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "As presented in the post, the problem is posed INCORRECTLY.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "It requests to find something that does not exist in the nature, \n" ); document.write( "contradicts to Math and can not be found.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |