document.write( "Question 314092: Hello,
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document.write( "I have to solve a linear equation but can not find a solution.
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document.write( "Please help me how to calculate.\r
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document.write( "x+y+z+u=1
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document.write( "2x+3y-4z+5u=2
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document.write( "3x+4y-3z+6u=0\r
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document.write( "Thank you sooo much in advance. \n" );
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Algebra.Com's Answer #224528 by Theo(13342)![]() ![]() You can put this solution on YOUR website! It appears there is no solution to this system of equations.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The fact becomes clear when you try to eliminate variables and wind up with an equation such as 0 = something that is not equal to 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since this equation is not true, the system of equations has no solution.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If you had come up with a row that says something like 0 = 0 which is true, then the system of equations would probably have had a dependent solution which means that the solution depends on the value of one of the variables.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since you started with a system of 3 equations in 4 unknowns, the best you could have hoped for would have been a dependent solution.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I will go through the solution to show you what happened.\r \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( "Your equations are:\r\n" ); document.write( "\r\n" ); document.write( " 1x + 1y + 1z + 1u = 1\r\n" ); document.write( " 2x + 3y - 4z + 5u = 2\r\n" ); document.write( " 3x + 4y - 3z + 6u = 0\r\n" ); document.write( "\r\n" ); document.write( "Subtract 2 times row 1 from row 2 to get:\r\n" ); document.write( "\r\n" ); document.write( " 0x + 1y - 6z + 3u = 0\r\n" ); document.write( "\r\n" ); document.write( "Subtract 3 times row 1 from row 3 to get:\r\n" ); document.write( "\r\n" ); document.write( " 0x + 1y - 6z + 3u = -3\r\n" ); document.write( "\r\n" ); document.write( "You are left with 2 equations in 3 unknowns.\r\n" ); document.write( "\r\n" ); document.write( "They are:\r\n" ); document.write( "\r\n" ); document.write( " 1y - 6z + 3u = 0\r\n" ); document.write( " 1y - 6z + 3u = -3\r\n" ); document.write( "\r\n" ); document.write( "If you subtract the first equation from the second equation you will get:\r\n" ); document.write( "\r\n" ); document.write( " 0 = -3\r\n" ); document.write( "\r\n" ); document.write( "Since 0 = -3 is false, this leads to the conclusion that there is no solution to this system of equations.\r\n" ); document.write( "\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "In order for there to be a unique solution to this system of equations, you would have had to have 4 equations in 4 unknowns.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |