document.write( "Question 64107This question is from textbook College Algebra with Modeling and Visualization
\n" ); document.write( ": Solve the system if possible.
\n" ); document.write( "2x-4y+2z=11
\n" ); document.write( "x+3y-2z=-9
\n" ); document.write( "4x-2y+z=7 \n" ); document.write( "
Algebra.Com's Answer #44899 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
This one can be solved without using the matrice
\n" ); document.write( ":
\n" ); document.write( "eq 1: 2x - 4y + 2z = 11
\n" ); document.write( "eq 2: x + 3y - 2z = -9
\n" ); document.write( "eq 3: 4x - 2y + z = 7
\n" ); document.write( ":
\n" ); document.write( "Adding equations 1 & 2 eliminates z
\n" ); document.write( "2x - 4y + 2z = 11
\n" ); document.write( " x + 3y - 2z = -9
\n" ); document.write( "------------------ add
\n" ); document.write( "3x - x + 0 = 2
\n" ); document.write( "3x - y = 2
\n" ); document.write( ":
\n" ); document.write( "Mult eq 3 by 2 and add it to eq 2, eliminating z again
\n" ); document.write( "8x - 4y + 2z = 14
\n" ); document.write( " x + 3y - 2z = -9
\n" ); document.write( "------------------ add
\n" ); document.write( "9x - y + 0 = 5
\n" ); document.write( "9x - y = 5
\n" ); document.write( ":
\n" ); document.write( "Subtract (3x - y = 2) from the above equation:
\n" ); document.write( "9x - y = 5
\n" ); document.write( "3x - y = 2
\n" ); document.write( "-------------subtract
\n" ); document.write( "6x + 0 = 3
\n" ); document.write( "x = 3/6
\n" ); document.write( "x = .5
\n" ); document.write( ":
\n" ); document.write( "Use 9x - y = 5 to find y, substitute .5 for x
\n" ); document.write( "9(.5) - y = 5
\n" ); document.write( "4.5 - y = 5
\n" ); document.write( "-y = 5 - 4.5
\n" ); document.write( "-y = .5
\n" ); document.write( "y = - .5
\n" ); document.write( ":
\n" ); document.write( "Find z using eq 2:
\n" ); document.write( "x + 3y - 2z = -9
\n" ); document.write( ".5 + 3(-.5) - 2z = -9
\n" ); document.write( ".5 - 1.5 - 2z = -9
\n" ); document.write( "-1 - 2z = -9
\n" ); document.write( "Get rid all those negative, mult eq by -1
\n" ); document.write( "1 + 2z = 9
\n" ); document.write( "2z = 9 -1
\n" ); document.write( "z = 8/2
\n" ); document.write( "z = +4
\n" ); document.write( ":
\n" ); document.write( "Our solution: x = +.5; y = -.5; z = +4
\n" ); document.write( "You can check it in equations 1 or 3:\r
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