document.write( "Question 819457: Can you help me solve this 3x3 equation:
\n" ); document.write( "2x+y-z=3
\n" ); document.write( "2x+2y-z=-1
\n" ); document.write( "-x-y+z=4 \n" ); document.write( "
Algebra.Com's Answer #493117 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
2x +y -z =3
\n" ); document.write( "2x +2y -z =-1
\n" ); document.write( "-x -y +z =4
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\n" ); document.write( "Make the 3rd row the 1st row:
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\n" ); document.write( "-x -y -z = 3
\n" ); document.write( "2x +y -z = 3
\n" ); document.write( "2x +2y -z = -1
\n" ); document.write( "--------
\n" ); document.write( "Add 2 times the 1st row to the 2nd and to the 3rd rows.
\n" ); document.write( "-x-y +z = 3
\n" ); document.write( "0 -y -3z = 9
\n" ); document.write( "0 +0 -3z = 5
\n" ); document.write( "-------
\n" ); document.write( "Solve the 3rd row for \"z\":
\n" ); document.write( "z = -5/3
\n" ); document.write( "--------
\n" ); document.write( "Substitute into the 2nd row and solve for \"y\":
\n" ); document.write( "-y -3*(-5/3) = 9
\n" ); document.write( "-y + 5 = 9
\n" ); document.write( "y = -4
\n" ); document.write( "--------------
\n" ); document.write( "Substitute into the 1st row and solve for \"x\":
\n" ); document.write( "-x -(-4) -(-5/3) = 3
\n" ); document.write( "-x + 12/3 +(5/3) = 3
\n" ); document.write( "-x + (17/3) = (9/3)
\n" ); document.write( "x = 8/3
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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