document.write( "Question 983164: X+2y+z=7
\n" ); document.write( "X+3z=11
\n" ); document.write( "2x-3y=1
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #603992 by ankor@dixie-net.com(22740)\"\" \"About 
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X + 2y + z = 7
\n" ); document.write( "X + 3z = 11
\n" ); document.write( "2x - 3y = 1
\n" ); document.write( ":
\n" ); document.write( "Use elimination here, multiply the 3rd equation by -1 and add
\n" ); document.write( "X + 2y + z = 7
\n" ); document.write( "X + 0y + 3z = 11
\n" ); document.write( "-2x + 3y + 0 = -1
\n" ); document.write( "-------------------Addition eliminates x
\n" ); document.write( "5y + 4z = 17
\n" ); document.write( "4z = -5y + 17
\n" ); document.write( "divide by 4
\n" ); document.write( "z = -1.25y + 4.25
\n" ); document.write( ":
\n" ); document.write( "Use elimination again on the 1st two equation
\n" ); document.write( "X + 0y + 3z = 11
\n" ); document.write( "X + 2y + z = 7
\n" ); document.write( "----------------subtraction eliminates x again
\n" ); document.write( "-2y + 2z = 4
\n" ); document.write( "simplify divide by 2
\n" ); document.write( "-y + z = 2
\n" ); document.write( "z = y + 2
\n" ); document.write( ":
\n" ); document.write( "z = z, therefore
\n" ); document.write( "y + 2 = -1.25y + 4.25
\n" ); document.write( "y + 1.25y = 4.25 - 2
\n" ); document.write( "2.25y = 2.25
\n" ); document.write( "y = 1
\n" ); document.write( "then
\n" ); document.write( "z = 1 + 2
\n" ); document.write( "z = 3
\n" ); document.write( "Find x using x + 3z = 11
\n" ); document.write( "x + 3(3) = 11
\n" ); document.write( "x = 11 - 9
\n" ); document.write( "x = 2
\n" ); document.write( ":
\n" ); document.write( "we have x=2; y=1; z=3
\n" ); document.write( ":
\n" ); document.write( "Check that in the 1st equation: x + 2y + z = 7, replace xyz
\n" ); document.write( "2 + 2(1) + 3 = 7
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