document.write( "Question 805699: use matrices and row operations to solve the following system;\r
\n" ); document.write( "\n" ); document.write( "2x+y+z=4
\n" ); document.write( "x+y-z=-3
\n" ); document.write( "5x-y+2z=23
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #485415 by stanbon(75887) $\"\"$ $\"About$

You can put this solution on YOUR website!
use matrices and row operations to solve the following system;
\n" ); document.write( "2x+y+z=4
\n" ); document.write( "x+y-z=-3
\n" ); document.write( "5x-y+2z=23
\n" ); document.write( "------
\n" ); document.write( "Rearrange::
\n" ); document.write( "x+y-z = -3
\n" ); document.write( "2x+y+z = 4
\n" ); document.write( "5x-y+2y = 23
\n" ); document.write( "-----------------
\n" ); document.write( "Subtract 2 times the 1st row from the 2nd row
\n" ); document.write( "Subtract 5 times the 1st row from the 3rd row
\n" ); document.write( "---------
\n" ); document.write( "x+y-z = -3
\n" ); document.write( "0-y+3z = 10
\n" ); document.write( "0-6y+7z = 38
\n" ); document.write( "--------------
\n" ); document.write( "Subtract 6 times the 2nd row from the 3rd:
\n" ); document.write( "x+y-z = -3
\n" ); document.write( "0-y+3z = 10
\n" ); document.write( "0+0-11z = -22
\n" ); document.write( "------
\n" ); document.write( "Solve the 3rd to get z = 2
\n" ); document.write( "Substitute into the 2nd to get: -y+3*2 = 10 ; y = -4
\n" ); document.write( "Substitute into the 1st to get: x -4 -2 = -3 ; x = 3
\n" ); document.write( "====================\r
\n" ); document.write( "\n" ); document.write( "Using the Matrix function of my TI-84 I checked my answer and got:
\n" ); document.write( "x = 3
\n" ); document.write( "y = -4
\n" ); document.write( "z = 2\r
\n" ); document.write( "\n" ); document.write( "==============
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "============== \n" ); document.write( "

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