document.write( "Question 244582: Solve the matrix equation: \r
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Algebra.Com's Answer #178856 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "First find the inverse of \"%28matrix%282%2C2%2C4%2C-5%2C1%2C2%29%29\":\r\n" );
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document.write( "To do that:\r\n" );
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document.write( "1.  Find the value of its determinant, \"abs%28matrix%282%2C2%2C4%2C-5%2C1%2C2%29%29=%284%29%282%29-%28-5%29%281%29+=+8%2B5+=+13\"\r\n" );
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document.write( "2. Swap the upper left and lower right elements of \"%28matrix%282%2C2%2C4%2C-5%2C1%2C2%29%29\",\r\n" );
document.write( "getting \"%28matrix%282%2C2%2C2%2C-5%2C1%2C4%29%29\"\r\n" );
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document.write( "3. Then change the signs of the upper right and lower left elements,\r\n" );
document.write( "getting \"%28matrix%282%2C2%2C2%2C5%2C-1%2C4%29%29\"\r\n" );
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document.write( "4. Divide every element by the value of the determinant of the \r\n" );
document.write( "original matrix which we found to be 13 in step 1, getting\r\n" );
document.write( "\"%28matrix%282%2C2%2C2%2F13%2C5%2F13%2C-1%2F13%2C4%2F13%29%29\". This is the inverse of\r\n" );
document.write( "the original matrix.\r\n" );
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document.write( "Left-multiply both sides of the given matrix equation:\r\n" );
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document.write( "by this inverse:\r\n" );
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document.write( "Use the associative principle to move the parentheses around\r\n" );
document.write( "the first two matrices on the left:\r\n" );
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document.write( "Do the matrix multiplication:\r\n" );
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document.write( "Simplify:\r\n" );
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document.write( "Simplify some more:\r\n" );
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document.write( "Simplify some more:\r\n" );
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document.write( "Multiply the matrices on the left:\r\n" );
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document.write( "\"%28matrix%282%2C1%2C1%2Am%2B0%2An%2C0%2Am%2B1%2An%29%29=%28matrix%282%2C1%2C3%2C-4%29%29\"\r\n" );
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document.write( "Simplify:\r\n" );
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document.write( "\"%28matrix%282%2C1%2Cm%2Cn%29%29=%28matrix%282%2C1%2C3%2C-4%29%29\"\r\n" );
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document.write( "Edwin
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