document.write( "Question 960486: Find the next three terms of the sequence 7,-20,61 \n" ); document.write( "
Algebra.Com's Answer #587066 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "7,-20,61\r\n" );
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document.write( "The first differences are -20-7 and 61-(-20) or -27 and 81\r\n" );
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document.write( "The second difference is 81-(-27) or 108\r\n" );
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document.write( "Make the table with the terms in the first column, the first\r\n" );
document.write( "differences in the second column and the third difference in\r\n" );
document.write( "the third column:\r\n" );
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document.write( "  7   -27   108\r\n" );
document.write( "-20    81\r\n" );
document.write( " 61\r\n" );
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document.write( "To get three more terms, extend the table by putting three more \r\n" );
document.write( "second differences of 108's in the last column:\r\n" );
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document.write( "  7   -27   108\r\n" );
document.write( "-20    81   108\r\n" );
document.write( " 61         108\r\n" );
document.write( "            108\r\n" );
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document.write( "Now work backward by adding.  That is:\r\n" );
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document.write( "Add the second 108 to the 81 just left of it, getting 189, \r\n" );
document.write( "and put that under the 81:\r\n" );
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document.write( "  7   -27   108\r\n" );
document.write( "-20    81   108\r\n" );
document.write( " 61   189   108\r\n" );
document.write( "            108\r\n" );
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document.write( "Add the 189 to the 61 just left of it, getting 250, \r\n" );
document.write( "and put that under the 61:\r\n" );
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document.write( "  7   -27   108\r\n" );
document.write( "-20    81   108\r\n" );
document.write( " 61   189   108\r\n" );
document.write( "250         108\r\n" );
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document.write( "Add the next 108 to the 189 just left of it, getting 297, \r\n" );
document.write( "and put that under the 189:\r\n" );
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document.write( "  7   -27   108\r\n" );
document.write( "-20    81   108\r\n" );
document.write( " 61   189   108\r\n" );
document.write( "250   297   108\r\n" );
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document.write( "Add the 297 to the 250 just left of it, getting 547, \r\n" );
document.write( "and put that under the 250:\r\n" );
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document.write( "  7   -27   108\r\n" );
document.write( "-20    81   108\r\n" );
document.write( " 61   189   108\r\n" );
document.write( "250   297   108\r\n" );
document.write( "547\r\n" );
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document.write( "So the sequence is now 7,-20,61,250,547, to 5 terms.\r\n" );
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document.write( "To get the 6th term do the same thing with the 108 at the bottom\r\n" );
document.write( "of the third column.  I won't tell you the 6th term, just to be mean. :)\r\n" );
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document.write( "Edwin
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