document.write( "Question 44751: equations with 3 linear variables\r
\n" ); document.write( "\n" ); document.write( "6x-4y+5z=31
\n" ); document.write( "5x+2y+2z=13
\n" ); document.write( "x+y+z=2\r
\n" ); document.write( "\n" ); document.write( "should you multiply the 2nd equation by 2?\r
\n" ); document.write( "\n" ); document.write( "show work
\n" ); document.write( "

Algebra.Com's Answer #29601 by venugopalramana(3286)\"\" \"About 
You can put this solution on YOUR website!
OK..THE PROBLEM,WE FACE IN ANSWERING IS THAT WE ARE NOT AWARE OF YOUR COURSE OF STUDY AND BACKGROUND.THE SOLUTION I GAVE IS BY GAUSS JORDAN ELIMINATION METHOD USED IN MATRICES AS WANTED BY SOME STUDENTS.IF YOU ARE NOT TAUGHT THAT ,WE SHALL DO BY NORMAL ELIMINATION.\r
\n" ); document.write( "\n" ); document.write( "equations with 3 linear variables
\n" ); document.write( "6x-4y+5z=31.......................................I
\n" ); document.write( "5x+2y+2z=13...........................II
\n" ); document.write( "x+y+z=2.......................III
\n" ); document.write( "EQN.II - 2*EQN.III
\n" ); document.write( "5X+2Y+2Z-2X-2Y-2Z=13-2*2=9
\n" ); document.write( "3X=9
\n" ); document.write( "X=9/3=3
\n" ); document.write( "EQN.I+4*EQN.III
\n" ); document.write( "6X-4Y+5Z+4X+4Y+4Z=31+4*2=39
\n" ); document.write( "10X+9Z=39...BUT...X=3..SO
\n" ); document.write( "10*3+9Z=39
\n" ); document.write( "9Z=39-30=9
\n" ); document.write( "Z=9/9=1
\n" ); document.write( "PUTTING IN EQN.III
\n" ); document.write( "3+Y+1=2
\n" ); document.write( "Y=2-4=-2
\n" ); document.write( "HOPE YOU UNDERSTOOD.
\n" ); document.write( "------------------------------------------------------------------------
\n" ); document.write( "SEE THE FOLLOWING AND TRY.IF STILL IN DIFFICULTY PLEASE COME BACK
\n" ); document.write( "YOU MAY MULTIPLY EQN.II WITH 2 AND ADD TO EQN.I TO ELIMINATE Y
\n" ); document.write( "x - y + z = 2
\n" ); document.write( "-x + y + z = 4
\n" ); document.write( "-x + z = 2
\n" ); document.write( "augmented matrix is
\n" ); document.write( "1.....................-1.......................1.............................2
\n" ); document.write( "-1.....................1.......................1.............................4
\n" ); document.write( "-1.....................0.......................1.............................2
\n" ); document.write( "nr2=r2+r1 and nr3=r3+r1
\n" ); document.write( "1..................-1.................1.............2
\n" ); document.write( "1-1=0............1-1=0............1+1=2..........2+4=6
\n" ); document.write( "1-1=0...........-1+0=-1...........1+1=2..........2+2=4
\n" ); document.write( "nr2=r2/2....nr3=r3-r2
\n" ); document.write( "1....................-1...............1..............2
\n" ); document.write( "0/2=0.............0/2=0..............2/2=1........6/2=3
\n" ); document.write( "0-0=0............-1-0=-1..............2-2=0.......4-6=-2
\n" ); document.write( "nr1=r1-r3-r2.......nr2=2r2........nr3=-r3
\n" ); document.write( "1-0-0=1............-1+1-0=0.........1-0-1=0.......2+2-3=1
\n" ); document.write( "0.....................0...................1............3
\n" ); document.write( "0.....................1...................0.............2
\n" ); document.write( "exchange r2 and r3
\n" ); document.write( "1....0........0.......1
\n" ); document.write( "0....1........0.......2
\n" ); document.write( "0....0........1.......3
\n" ); document.write( "he\r
\n" ); document.write( "\n" ); document.write( "nce x=1......y=2.....z=3
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