document.write( "Question 985432: This was on a Hero's episode (Season 4, Episode 1) that never showed the solution, and thought I would place it up here as I came up with 2 answer myself, was wanting validation to my answer: (w=0,x=12/5,y=19/5,z=0) or (w=1, x=1, y=1, and z=1), the second set of answers I never actually worked out to be that, I just saw that answer automatically in my head, and it does indeed work, but I am unsure how to show the work for it, and would love someone to walk me through that if they wouldn't mind.\r
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document.write( "x + 2y + 3w + 4z = 10\r
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document.write( "2x - y + w - z = 1\r
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document.write( "3x + y + 4w + 3z = 11\r
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document.write( "-2x + 6y + 4w + 10z = 18
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Algebra.Com's Answer #606256 by ikleyn(52803)![]() ![]() You can put this solution on YOUR website! \r \n" ); document.write( "\n" ); document.write( "The determinant of the 4x4 matrix of this system is equal to zero.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So, the matrix is singular, actually.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Therefore, it is not amazing that you found two solutions of the system. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Indeed, there are infinitely many solutions. \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The trick: I did not calculate the determinant myself.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I simply asked GOOGLE, and it pointed me to this solver (online calculator):\r \n" ); document.write( "\n" ); document.write( "http://ncalculators.com/matrix/4x4-matrix-determinant-calculator.htm \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I don't know why, but I trust to this result. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |