document.write( "Question 1170814: Solve the following system :\r
\n" ); document.write( "\n" ); document.write( "-9x + 3y -2z = 61\r
\n" ); document.write( "\n" ); document.write( "8x + 7y + 5z = -138\r
\n" ); document.write( "\n" ); document.write( "5x - 5y + 8z = -45
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #795691 by Alan3354(69443) $\"\"$ $\"About$

You can put this solution on YOUR website!
Solve the following system :\r
\n" ); document.write( "\n" ); document.write( "-9x + 3y -2z = 61\r
\n" ); document.write( "\n" ); document.write( "8x + 7y + 5z = -138\r
\n" ); document.write( "\n" ); document.write( "5x - 5y + 8z = -45
\n" ); document.write( "------------------------------------
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\r\n" );
document.write( "-36x + 12y -8z = 244 --- 1st eqn times 4\r\n" );
document.write( " 5x - 5y + 8z = -45\r\n" );
document.write( "---------------------------- Add\r\n" );
document.write( "-31x + 7y = 199 ---- z eliminated  (Eqn A)\r\n" );
document.write( "===================\r\n" );
document.write( "-45x + 15y - 10z = 305 --- 1st eqn times 5\r\n" );
document.write( " 16x + 14y + 10z = -276 --- 2nd eqn times 2\r\n" );
document.write( "-------------------------------------------------- Add\r\n" );
document.write( "-29x + 29y = 29\r\n" );
document.write( " -x + y = 1 --- z eliminated (Eqn B)\r\n" );
document.write( "============================\r\n" );
document.write( "-31x + 7y = 199\r\n" );
document.write( " -7x + 7y = 7  Eqn B times 7\r\n" );
document.write( "----------------------------------------\r\n" );
document.write( "Subtract\r\n" );
document.write( "-24x = 192\r\n" );
document.write( "x = -8\r\n" );
document.write( "---------------\r\n" );
document.write( "Sub for x in Eqn B find y\r\n" );
document.write( "Sub x & y in any eqn and find z\r\n" );
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