document.write( "Question 56375: please solve the system
\n" ); document.write( "x-y+2z=7
\n" ); document.write( "2x+z=4
\n" ); document.write( "x+5y+z=9 \n" ); document.write( "

Algebra.Com's Answer #38330 by AgusKwan(7) $\"\"$ $\"About$

You can put this solution on YOUR website!
x-y+2z=7 --> Equation1
\n" ); document.write( "2x+z=4 --> Equation2
\n" ); document.write( "x+5y+z=9 --> Equation3\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since Equation2 only have x and z variable, we'll eliminate y from the other 2 equation \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Equation1 --> x-y+2z=7 (times 5) --> 5x - 5y + 10z = 35
\n" ); document.write( "Equation3 --> x+5y+z=9 ------------> x + 5y + z = 9 (add both equations)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "will have 6x + 11z = 44 --> Equation 4\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Equation 4 --> 6x + 11z = 44------------> 6x + 11z = 44
\n" ); document.write( "Equation 2 --> 2x + z = 4 (times 3)---> 6x + 3z = 12 (subtract equations)
\n" ); document.write( "8z = 32
\n" ); document.write( "z = 4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Substitute z on Equation2 --> 2x + 4 =4 --> x=0\r
\n" ); document.write( "\n" ); document.write( "Substitute z and x to Equation1 --> 0-y+2(4)=7 --> y=1\r
\n" ); document.write( "\n" ); document.write( "Therefore x=0 , y=1, z=4 \n" ); document.write( "

\n" );