document.write( "Question 1118042: Use matrices to solve the system of equations.\r
\n" ); document.write( "\n" ); document.write( "2x+4y=2\r
\n" ); document.write( "\n" ); document.write( "-3x+y=11 \n" ); document.write( "

Algebra.Com's Answer #733238 by Alan3354(69443) $\"\"$ $\"About$

You can put this solution on YOUR website!
2x+4y=2\r
\n" ); document.write( "\n" ); document.write( "-3x+y=11
\n" ); document.write( "--------------------------
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\r\n" );
document.write( "\r\n" );
document.write( "| 2   4   -2|\r\n" );
document.write( "|-3   1  -11|\r\n" );
document.write( "

\n" ); document.write( "Det = 2*1 - (-3)*4 = 14
\n" ); document.write( "---
\n" ); document.write( "x*Det = 4*-11 + 1*2 = -42
\n" ); document.write( "x = -3
\n" ); document.write( "------
\n" ); document.write( "-y*Det = 2*-11 - 6 = -28
\n" ); document.write( "y = 2
\n" ); document.write( "=============
\n" ); document.write( "A different method, I think the method you mentioned.
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\r\n" );
document.write( "\r\n" );
document.write( "| 2   4    2|\r\n" );
document.write( "|-3   1   11|\r\n" );
document.write( "---------------\r\n" );
document.write( "| 1   2    1|  /2\r\n" );
document.write( "|-6   2   22|  times 2\r\n" );
document.write( "---------------  Subtract --> Row 1\r\n" );
document.write( "| 7   0  -21|  /7\r\n" );
document.write( "|-3   1   11|\r\n" );
document.write( "---------------\r\n" );
document.write( "| 1   0   -3|\r\n" );
document.write( "|-3   1   11|\r\n" );
document.write( "---------------\r\n" );
document.write( "| 3   0   -9|  times 3\r\n" );
document.write( "|-3   1   11|\r\n" );
document.write( "--------------- Add --> row 2\r\n" );
document.write( "| 1   0   -3|\r\n" );
document.write( "| 0   1    2|\r\n" );
document.write( "\r\n" );
document.write( "

\n" ); document.write( "Same answers, the hard way.
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