document.write( "Question 564321: What are the w, x, y, and z values using this matrix?
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Algebra.Com's Answer #365322 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "This matrix is in \"row echelon\" form because each\r\n" );
document.write( "row's left-most non-zero element is 1 and they\r\n" );
document.write( "move to the right as we go down the matrix.  So the\r\n" );
document.write( "matrix is an abbreviation for this system:\r\n" );
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document.write( "Removing all the 1 coefficients and the 0 terms:\r\n" );
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document.write( "We use \"back substitution\".\r\n" );
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document.write( "The bottom, fourth, equation is already solved for z,\r\n" );
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document.write( "so we substitute -2 for z in the third equation:\r\n" );
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document.write( "\"y+%2B+expr%283%2F5%29z+=+9%2F5\"\r\n" );
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document.write( "\"y+%2B+expr%283%2F5%29%28-2%29+=+9%2F5\"\r\n" );
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document.write( "\"y+-+6%2F5+=+9%2F5\"\r\n" );
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document.write( "\"y+=+9%2F5+%2B+6%2F5\"\r\n" );
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document.write( "\"y+=+15%2F5\"\r\n" );
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document.write( "\"y+=+3\"\r\n" );
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document.write( "Now we substitute 3 for y and -2 for z in the\r\n" );
document.write( "second equation:\r\n" );
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document.write( "\"x++%2B++4y+%2B+++3z+=+8\"\r\n" );
document.write( "\"x++%2B++4%283%29+%2B++3%28-2%29+=+8\"\r\n" );
document.write( "\"x+%2B+12+-+6+=+8\"\r\n" );
document.write( "\"x+%2B+6+=+8\"\r\n" );
document.write( "\"x+=+2\"\r\n" );
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document.write( "Finally we substitute 2 for x, 3 for y \r\n" );
document.write( "and -2 for z in the first equation:\r\n" );
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document.write( "\"w+++%2Bx++%2B++y+%2B+++z+=+++4\"\r\n" );
document.write( "\"w%2B2+%2B+3+-+2+=+4\"\r\n" );
document.write( "\"w+%2B3+=+4\"\r\n" );
document.write( "\"w=1\"\r\n" );
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document.write( "Solution (w,x,y,z) = (1,2,3,-2)\r\n" );
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document.write( "Edwin
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