document.write( "Question 880182: 1,4,20,126,? \n" ); document.write( "
Algebra.Com's Answer #531267 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
Question 880183
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document.write( "Put them in a column\r\n" );
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document.write( "  1\r\n" );
document.write( "  4\r\n" );
document.write( " 20\r\n" );
document.write( "126\r\n" );
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document.write( "Subtract each number from the one below it and write it out\r\n" );
document.write( "to the side in a new column:\r\n" );
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document.write( "  1   3\r\n" );
document.write( "  4  16 \r\n" );
document.write( " 20 106\r\n" );
document.write( "126\r\n" );
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document.write( "In the 2nd column subtract each number from the one below it and \r\n" );
document.write( "write it out to the side in a new column:\r\n" );
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document.write( "  1   3  13  77 \r\n" );
document.write( "  4  16  90\r\n" );
document.write( " 20 106\r\n" );
document.write( "126\r\n" );
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document.write( "In the 3rd column subtract each (the only) number from the one below \r\n" );
document.write( "it (the only one below it) and  write it out to the side in a new column:\r\n" );
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document.write( "  1   3  13  77\r\n" );
document.write( "  4  16  90\r\n" );
document.write( " 20 106\r\n" );
document.write( "126\r\n" );
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document.write( "Now that we have completed the difference table,\r\n" );
document.write( "write another 77 underneath the last number 77\r\n" );
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document.write( "  1   3  13  77\r\n" );
document.write( "  4  16  90  77\r\n" );
document.write( " 20 106\r\n" );
document.write( "126\r\n" );
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document.write( "Add the 77 and the 90, getting 167 and write that underneath \r\n" );
document.write( "the 90\r\n" );
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document.write( "  1   3  13  77\r\n" );
document.write( "  4  16  90  77\r\n" );
document.write( " 20 106 167\r\n" );
document.write( "126\r\n" );
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document.write( "Add the 167 and the 106, getting 273, and write that underneath \r\n" );
document.write( "the 106:\r\n" );
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document.write( "  1   3  13  77\r\n" );
document.write( "  4  16  90  77\r\n" );
document.write( " 20 106 251\r\n" );
document.write( "126 273\r\n" );
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document.write( "Finally, add the 273 and the 126, getting 399, and write that underneath \r\n" );
document.write( "the 126:\r\n" );
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document.write( "  1   3  13  77\r\n" );
document.write( "  4  16  90  77\r\n" );
document.write( " 20 106 251\r\n" );
document.write( "126 273\r\n" );
document.write( "399\r\n" );
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document.write( "Answer: fifth term = 399\r\n" );
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document.write( "There is a way to get the nth term formula:\r\n" );
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document.write( "\"%2877n%5E3-423n%5E2%2B748n-396%29%2F6\"\r\n" );
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document.write( "Substitute n=1\r\n" );
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document.write( "\"%2877n%5E3-423n%5E2%2B748n-396%29%2F6\" = \"%2877%281%29%5E3-423%281%29%5E2%2B748%281%29-396%29%2F6\" = \"6%2F6\" = 1\r\n" );
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document.write( "Substitute n=2\r\n" );
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document.write( "\"%2877n%5E3-423n%5E2%2B748n-396%29%2F6\" = \"%2877%282%29%5E3-423%282%29%5E2%2B748%282%29-396%29%2F6\" =\"24%2F6\" = 4\r\n" );
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document.write( "Substitute n=3\r\n" );
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document.write( "\"%2877n%5E3-423n%5E2%2B748n-396%29%2F6\" = \"%2877%283%29%5E3-423%283%29%5E2%2B748%283%29-396%29%2F6\" = \"120%2F6\" = 20\r\n" );
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document.write( "Substitute n=4\r\n" );
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document.write( "\"%2877n%5E3-423n%5E2%2B748n-396%29%2F6\" = \"%2877%284%29%5E3-423%284%29%5E2%2B748%284%29-396%29%2F6\" = \"1008%2F6\" = 168\r\n" );
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document.write( "Substitute n=5\r\n" );
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document.write( "\"%2877n%5E3-423n%5E2%2B748n-396%29%2F6\" = \"%2877%285%29%5E3-423%285%29%5E2%2B748%285%29-396%29%2F6\" = \"2394%2F6\" = 399\r\n" );
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document.write( "Edwin
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