document.write( "Question 1106479: Use matrices to solve the system of equations.
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Algebra.Com's Answer #721492 by Edwin McCravy(20056) $\"\"$ $\"About$
You can put this solution on YOUR website!
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document.write( "2x+y+2z=4\r\n" );
document.write( "2x+2y  =5\r\n" );
document.write( "2x- y+6z=2\r\n" );
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document.write( "Write it this way, putting in 1 coefficients and 0z\r\n" );
document.write( "fo the missing z-term in the second equation.\r\n" );
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document.write( "2x + 1y + 2z = 4\r\n" );
document.write( "2x + 2y + 0z = 5\r\n" );
document.write( "2x - 1y + 6z = 2\r\n" );
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document.write( "Then do it step by step just like this one:\r\n" );
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document.write( "x+y+z = 6\r\n" );
document.write( "2x-y+z = 3\r\n" );
document.write( "x+2y-3z = -4\r\n" );
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document.write( "Write it this way:\r\n" );
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document.write( "1x + 1y + 1z =  6\r\n" );
document.write( "2x - 1y + 1z =  3\r\n" );
document.write( "1x + 2y - 3z = -4\r\n" );
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document.write( "Cramer's rule:\r\n" );
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document.write( "There are 4 columns,\r\n" );
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document.write( "1. The column of x-coefficients \r\n" );
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document.write( "2. The column of y-coefficients \r\n" );
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document.write( "3. The column of z-coefficients  \r\n" );
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document.write( "4. The column of constants:     \r\n" );
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document.write( "There are four determinants:\r\n" );
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document.write( "1. The determinant  consists of just the three columns\r\n" );
document.write( "of x, y, and z coefficients. in that order, but does not\r\n" );
document.write( "contain the column of constants.\r\n" );
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document.write( "It has value .  I'm assuming you know how to find the\r\n" );
document.write( "value of a 3x3 determinant, for that's a subject all by itself.\r\n" );
document.write( "If you don't know how, ask me how in the note form below and I'll\r\n" );
document.write( "get back to you by email.  No charge. \r\n" );
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document.write( "2. The determinant  is like the determinant \r\n" );
document.write( "except that the column of x-coefficients is replaced by the\r\n" );
document.write( "column of constants.   does not contain the column \r\n" );
document.write( "of x-coefficients.\r\n" );
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document.write( "It has value .\r\n" );
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document.write( "3. The determinant  is like the determinant \r\n" );
document.write( "except that the column of y-coefficients is replaced by the\r\n" );
document.write( "column of constants.   does not contain the column \r\n" );
document.write( "of y-coefficients.\r\n" );
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document.write( "It has value .\r\n" );
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document.write( "4. The determinant  is like the determinant \r\n" );
document.write( "except that the column of z-coefficients is replaced by the\r\n" );
document.write( "column of constants.   does not contain the column \r\n" );
document.write( "of z-coefficients.\r\n" );
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document.write( ".\r\n" );
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document.write( "It has value .\r\n" );
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document.write( "Now the formulas for x, y and z are\r\n" );
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document.write( "Edwin
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