document.write( "Question 80447: You have to solve the equations using matrices. I can get part of the answer correct but not the whole answer. I can solve for y, but what I come up with for x is not correct according to the book. The two equations are:
\n" ); document.write( "12x + 2y = 2 and 6x - 3y = -11\r
\n" ); document.write( "\n" ); document.write( "I can come up with 3 for y but I end up with -11/6 for x and the book says it should be -1/3. I can't figure out how to get the -1/3. \n" ); document.write( "

Algebra.Com's Answer #57760 by Edwin McCravy(20056) $\"\"$ $\"About$

You can put this solution on YOUR website!
: You have to solve the equations using matrices. I can get part of the answer correct but not the whole answer. I can solve for y, but what I come up with for x is not correct according to the book. The two equations are:
\n" ); document.write( "12x + 2y = 2 and 6x - 3y = -11
\n" ); document.write( "I can come up with 3 for y but I end up with -11/6 for x and the book says it should be -1/3. I can't figure out how to get the -1/3.
\n" ); document.write( "

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document.write( "12x + 2y =   2\r\n" );
document.write( " 6x - 3y = -11\r\n" );
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document.write( "[12   2 |   2]\r\n" );
document.write( "[ 6  -3 | -11]\r\n" );
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document.write( "Get a 0 where the 6 is by adding -1 \r\n" );
document.write( "times the top row to 2 times the \r\n" );
document.write( "bottom row:\r\n" );
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document.write( "-1[12   2 |   2]\r\n" );
document.write( " 2[ 6  -3 | -11]\r\n" );
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document.write( "  [12   2 |   2]\r\n" );
document.write( "  [ 0  -8 | -24]\r\n" );
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document.write( "Get a 0 where the first 2 is in the top\r\n" );
document.write( "row by adding 1 times the bottom\r\n" );
document.write( "row to 4 times the top row\r\n" );
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document.write( " 4[12   2 |   2]\r\n" );
document.write( " 1[ 0  -8 | -24]\r\n" );
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document.write( "  [48   0 | -16] \r\n" );
document.write( "  [ 0  -8 | -24]\r\n" );
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document.write( "Now divide the top row thru by 48\r\n" );
document.write( "and the bottom row by -8:\r\n" );
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document.write( "  [1  0 | -1/3]\r\n" );
document.write( "  [0  1 |   3 ]\r\n" );
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document.write( "So the solution is x = -1/3, y = 3\r\n" );
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document.write( "Edwin

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