document.write( "Question 14059: x-4y+3z=-27
\n" ); document.write( "2x+2y-3z=22
\n" ); document.write( "4z=-16 \n" ); document.write( "

Algebra.Com's Answer #7071 by rahman(247) $\"\"$ $\"About$

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4z=-16
\n" ); document.write( " $\"4z%2F4=-16%2F4\"$
\n" ); document.write( "z=-4\r
\n" ); document.write( "\n" ); document.write( "Substitute z= -4 to the first and the second equation:
\n" ); document.write( "x-4y+3z=-27
\n" ); document.write( "x-4y+3(-4)=-27
\n" ); document.write( "x-4y-12=-27
\n" ); document.write( "x-4y=-27+12
\n" ); document.write( "x-4y=-15 ..........(i)\r
\n" ); document.write( "\n" ); document.write( "2x+2y-3z=22
\n" ); document.write( "2x+2y-3(-4)=22
\n" ); document.write( "2x+2y+12=22
\n" ); document.write( "2x+2y=22-12
\n" ); document.write( "2x+2y=10 --------->divide by 2
\n" ); document.write( "x + y = 5 .........(ii)\r
\n" ); document.write( "\n" ); document.write( "Use elimination method:
\n" ); document.write( "x-4y=-15
\n" ); document.write( "x+y = 5
\n" ); document.write( "-------- -
\n" ); document.write( "-5y=-20
\n" ); document.write( " $\"%28-5y%29%2F%28-5%29=%28-20%29%2F%28-5%29\"$
\n" ); document.write( "y=4\r
\n" ); document.write( "\n" ); document.write( "Substitute y=4 to (ii):
\n" ); document.write( "x + y = 5
\n" ); document.write( "x + 4 = 5
\n" ); document.write( "x = 1\r
\n" ); document.write( "\n" ); document.write( "So, the solution are x=1, y=4 and z=-4
\n" ); document.write( "OK \n" ); document.write( "

\n" );