document.write( "Question 316054: 
Row echelon form of a system of linear equation is:\r\n" );
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document.write( "1   2  4  0  =  1\r\n" );
document.write( "0   1 -1  2  =  2\r\n" );
document.write( "0   0  1  3  =  0\r\n" );
document.write( "0   0  0  1  = -2\r\n" );
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document.write( "a) write the system of equations corresponding to this matrix.  us x1 x2 x3 x4 as variables.  \r\n" );
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document.write( "My answer: x1+2x2+4x3 = 1; x2-x3+2x4 = 2; x3+3x4 = 0; and x4= -2\r\n" );
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document.write( "b) determine whether the system is consistent or inconsistent.  if consistent, give the solution.  My answer:\r\n" );
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document.write( "from the equations above:\r\n" );
document.write( "we know x4 = -2 so plug into\r\n" );
document.write( "x3+3(-2)=0 solve for x3\r\n" );
document.write( "    x3-6=0\r\n" );
document.write( "      +6=0+6\r\n" );
document.write( "      x3=6\r\n" );
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document.write( "we know x4=-2 and x3=6 plug into\r\n" );
document.write( "x2-(6)+2(-2)=2\r\n" );
document.write( "       x2-10=2+10\r\n" );
document.write( "    x2-10+10=12\r\n" );
document.write( "          x2=12\r\n" );
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document.write( "we know x4=-2; x3=6; x2=12 plug into\r\n" );
document.write( "x1+2(12)+4(6)=1\r\n" );
document.write( "     x1+24+24=1\r\n" );
document.write( "           x1=-48+1\r\n" );
document.write( "           x1=47\r\n" );
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document.write( "Can you let me know if this is correct?  If not please help me where I have it wrong.  Thank you!\r\n" );
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Algebra.Com's Answer #226085 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Everything's fine except the last step\r\n" );
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document.write( "x1=-48+1\r\n" );
document.write( "x1=47 \r\n" );
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document.write( "The last step should be\r\n" );
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document.write( "x1=-47\r\n" );
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document.write( "You knew that. You just mistyped.\r\n" );
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document.write( "Edwin
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