document.write( "Question 163437This question is from textbook College Algebra
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Algebra.Com's Answer #120451 by Edwin McCravy(20056) $\"\"$ $\"About$

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Three solutions to the equation Ax-By-Cz-5=0 are (2,4,-1),(3,6,-2), and(-2,-9,-4). Find C.
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document.write( "Substitute the first solution: (x,y,z)=(2,4,-1) in\r\n" );
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document.write( "Ax-By-Cz-5=0\r\n" );
document.write( "A(2)-B(4)-C(-1)-5=0\r\n" );
document.write( "2A-4B+C-5=0\r\n" );
document.write( "2A-4B+C=5\r\n" );
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document.write( "Substitute the second solution: (x,y,z)=(3,6,-2), in\r\n" );
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document.write( "Ax-By-Cz-5=0\r\n" );
document.write( "A(3)-B(6)-C(-2)-5=0\r\n" );
document.write( "3A-6B+2C-5=0\r\n" );
document.write( "3A-6B+2C=5\r\n" );
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document.write( "Substitute the third solution: (x,y,z)=(-2,-9,-4), in\r\n" );
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document.write( "Ax-By-Cz-5=0\r\n" );
document.write( "A(-2)-B(-9)-C(-4)-5=0\r\n" );
document.write( "-2A+9B+4C-5=0\r\n" );
document.write( "-2A+9B+4C=5\r\n" );
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document.write( "So you have this system of three equations in three\r\n" );
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document.write( "Do you know how to solve that system?  If not post\r\n" );
document.write( "again.  The solution to that system is \r\n" );
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document.write( "All you were asked for was C, which is -5.\r\n" );
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document.write( "To check, the equation \r\n" );
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document.write( "Check to see if (2,4,-1) is a solution to\r\n" );
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document.write( "Check to see if (3,6,-2) is a solution to\r\n" );
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document.write( "Check to see if (-2,-9,-4) is a solution to\r\n" );
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document.write( "So the problem checks.\r\n" );
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document.write( "Edwin

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