document.write( "Question 974248: 4x+2y-z=7;
\n" ); document.write( "8x-2y+z=17 \n" ); document.write( "

Algebra.Com's Answer #596221 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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4x+2y-z=7;
\n" ); document.write( " 8x-2y+z=17
\n" ); document.write( "--------------adding eliminates y and z
\n" ); document.write( "12x + 0 + 0 = 24
\n" ); document.write( "x = 24/12
\n" ); document.write( "x = 2
\n" ); document.write( ":
\n" ); document.write( "Replace x with 2 in both equations
\n" ); document.write( "4(2) + 2y - z = 7
\n" ); document.write( "8 + 2y - z = 7
\n" ); document.write( "2y - z = 7 - 8
\n" ); document.write( "2y - z = -1
\n" ); document.write( "and
\n" ); document.write( "8(2) - 2y + z = 17
\n" ); document.write( "-2y + z = 17 - 16
\n" ); document.write( "-2y + z = 1
\n" ); document.write( "multiply by -1
\n" ); document.write( "2y - z = -1
\n" ); document.write( ":
\n" ); document.write( "you can see these two equation are the same, all we can be sure of is x = 2 \n" ); document.write( "

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