document.write( "Question 475595:
\n" ); document.write( "Please help me solve the system of equation:\r
\n" ); document.write( "\n" ); document.write( " -2x-5y-z=57
\n" ); document.write( " -5y-2z=54
\n" ); document.write( " -5z=35\r
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Algebra.Com's Answer #326128 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "  -2x-5y-1z=57\r\n" );
document.write( "     -5y-2z=54\r\n" );
document.write( "        -5z=35\r\n" );
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document.write( "That is in echelon (or triangular) form.\r\n" );
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document.write( "You start at the bottom and work your way to the top.\r\n" );
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document.write( "Start by solving the bottom equation first:\r\n" );
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document.write( "        -5z=35\r\n" );
document.write( "          z=-7\r\n" );
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document.write( "Now substitute z=-7 in the middle equation:\r\n" );
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document.write( "     -5y-2z=54\r\n" );
document.write( "  -5y-2(-7)=54\r\n" );
document.write( "     -5y+14=54\r\n" );
document.write( "        -5y=40\r\n" );
document.write( "          y=-8\r\n" );
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document.write( "Now substitute z=-7 and y=-8 in the top equation:\r\n" );
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document.write( "      -2x-5y-z=57\r\n" );
document.write( "-2x-5(-8)-(-7)=57\r\n" );
document.write( "      -2x+40+7=57\r\n" );
document.write( "        -2x+47=57\r\n" );
document.write( "           -2x=10\r\n" );
document.write( "             x=-5\r\n" );
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document.write( "(x,y,z) = (-5,-8,-7)\r\n" );
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document.write( "Edwin
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