document.write( "Question 560099: find the inverse of the following matrices.
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Algebra.Com's Answer #363699 by Edwin McCravy(20060) $\"\"$ $\"About$

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document.write( "Augment the matrix with the identity matrix with the \r\n" );
document.write( "same dimensions (4×4):\r\n" );
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document.write( "We will use row operations until we get the identity on the left.\r\n" );
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document.write( "Multiply row 1 by -1 and add it to row 2:\r\n" );
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document.write( "Multiply row 1 by -1 and add it to row 3:\r\n" );
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document.write( "Multiply row 1 by -1 and add it to row 4:\r\n" );
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document.write( "Multiply row 2 by -1 and add it to row 1:\r\n" );
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document.write( "Multiply row 2 by 2 and add it to row 3:\r\n" );
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document.write( "Multiply row 2 by -2 and add it to row 4:\r\n" );
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document.write( "Add row 3 to row 1:\r\n" );
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document.write( "Multiply row 3 by 2 and add to row 4:\r\n" );
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document.write( "To avoid fractions multiply row 3 by -2 and row 2 by 3:\r\n" );
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document.write( "Add row 3 to row 2:\r\n" );
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document.write( "Again to avoid fractions multiply row 4 by 2 and row 1 by -3:\r\n" );
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document.write( "Add row 4 to row 1:\r\n" );
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document.write( "To avoid fractions multiply row 2 by 6:\r\n" );
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document.write( "Add row 4 to row 2:\r\n" );
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document.write( "To avoid fractions multiply row 4 by 2 and row 3 by 3:\r\n" );
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document.write( "Add row 4 to row 3:\r\n" );
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document.write( "Now get 1's on the diagonal:\r\n" );
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document.write( "Divide row 1 by -3\r\n" );
document.write( "Divide row 2 by 18\r\n" );
document.write( "Divide row 3 by 18\r\n" );
document.write( "Divide row 4 by 12\r\n" );
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document.write( "Now that we have the identity on the left, the \r\n" );
document.write( "augmented part is the inverse:\r\n" );
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document.write( "Edwin

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