document.write( "Question 365789: determine whether the matrix has an inverse. if an inverse matrix exists, find it. \"%28matrix%282%2C2%2C2%2C-1%2C1%2C0%29%29\"
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Algebra.Com's Answer #260728 by Edwin McCravy(20063)\"\" \"About 
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document.write( "To find the inverse of a 2x2 matrix:\r\n" );
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document.write( "1. Calculate the determinant by the rule:\r\n" );
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document.write( "upper left element times lower right element minus\r\n" );
document.write( "upper right element times lower left element\r\n" );
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document.write( "2. Exchange the upper left and lower right elements.\r\n" );
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document.write( "3. Change the signs of the upper right and lower left elements.\r\n" );
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document.write( "4. Divide each element by the value of the determinant found\r\n" );
document.write( "   in step 1.\r\n" );
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document.write( "Find the determinant of \"%28matrix%282%2C2%2C2%2C-1%2C1%2C0%29%29\"\r\n" );
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document.write( "Here are those steps done with your matrix.\r\n" );
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document.write( "1. \"%282%29%280%29-%28-1%29%281%29+=+0%2B1=1\"\r\n" );
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document.write( "2. \"%28matrix%282%2C2%2C0%2C-1%2C1%2C2%29%29\"\r\n" );
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document.write( "3. \"%28matrix%282%2C2%2C0%2C1%2C-1%2C2%29%29\"\r\n" );
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document.write( "4. \"%28matrix%282%2C2%2C0%2F1%2C1%2F1%2C-1%2F1%2C2%2F1%29%29\", simplifying,\r\n" );
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document.write( "The inverse matrix is:\r\n" );
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document.write( "\"%28matrix%282%2C2%2C0%2C1%2C-1%2C2%29%29\"\r\n" );
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document.write( "-------------------------------\r\n" );
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document.write( "Checking to see if it really is the inverse matrix:\r\n" );
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document.write( "Multiply the original matrix by it:\r\n" );
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document.write( "\"%28matrix%282%2C2%2C0%2C1%2C-1%2C2%29%29\"\"%28matrix%282%2C2%2C2%2C-1%2C1%2C0%29%29\"\r\n" );
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document.write( "\"%28matrix%282%2C2%2C0%2B1%2C0%2B0%2C-2%2B2%2C1%2B0%29%29\"\r\n" );
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document.write( "\"%28matrix%282%2C2%2C1%2C0%2C0%2C1%29%29\"\r\n" );
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document.write( "which is the identity matrix, so the inverse is correct.\r\n" );
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document.write( "Edwin

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