document.write( "Question 160700: Use elimination method to solve the system.
\n" ); document.write( "-4x+4y-2z=-8
\n" ); document.write( "-3x-y+4z=0
\n" ); document.write( "2x-2y+3z=-4 \n" ); document.write( "
Algebra.Com's Answer #118557 by ankor@dixie-net.com(22740)\"\" \"About 
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-4x + 4y - 2z =-8
\n" ); document.write( "-3x - y + 4z = 0
\n" ); document.write( "+2x- 2y + 3z =-4
\n" ); document.write( ":
\n" ); document.write( "The coefficients of the 1st and 3rd equations, will help us alot:
\n" ); document.write( ":
\n" ); document.write( "Multiply the 3rd equation by 2, and add to the 1st equation
\n" ); document.write( "-4x + 4y - 2z = -8
\n" ); document.write( "+4x - 4y + 6z = -8
\n" ); document.write( "---------------------adding eliminates x and y, find z
\n" ); document.write( "0x + 0y + 4z = -16
\n" ); document.write( "z = \"-16%2F4\"
\n" ); document.write( "z = -4
\n" ); document.write( ":
\n" ); document.write( "Substitute -4 for z in the 2nd equation
\n" ); document.write( "-3x - y + 4(-4) = 0
\n" ); document.write( "-3x - y - 16 = 0
\n" ); document.write( "-3x - y = 16
\n" ); document.write( ":
\n" ); document.write( "Substitute -4 for z in the 3rd equation:
\n" ); document.write( "+2x - 2y + 3(-4) = -4
\n" ); document.write( "+2x - 2y - 12 = -4
\n" ); document.write( "+2x - 2y = -4 + 12
\n" ); document.write( "+2x - 2y = +8
\n" ); document.write( ":
\n" ); document.write( "Multiply -3x - y = 16 by -2 and add to the above equaiton
\n" ); document.write( "+6x + 2y = -32
\n" ); document.write( "+2x - 2y = 8
\n" ); document.write( "---------------- addition eliminate y
\n" ); document.write( "8x = -24
\n" ); document.write( "x = \"%28-24%29%2F8\"
\n" ); document.write( "x = -3
\n" ); document.write( ":
\n" ); document.write( "Find y using the 2nd equation, substitute for x & z
\n" ); document.write( "-3(-3) - y + 4(-4) = 0
\n" ); document.write( "+9 - y - 16 = 0
\n" ); document.write( "-y -7 = 0
\n" ); document.write( "-y = +7
\n" ); document.write( "y = -7
\n" ); document.write( ":
\n" ); document.write( "Solutions: x=-3, y=-7; z=-4
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check solutions in the 3rd equation:
\n" ); document.write( "+2x- 2y + 3z =-4
\n" ); document.write( "2(-3) - 2(-7) + 3(-4) = -4
\n" ); document.write( "-6 + 14 - 12 = -4
\n" ); document.write( "-18 + 14 = -4 \n" ); document.write( "
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