document.write( "Question 674615: Consider the sequence:6;6;2;-6;-18\r
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Algebra.Com's Answer #419345 by solver91311(24713)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "Use the method of common differences:\r
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document.write( "      6     6     2    -6   -18\r\n" );
document.write( "       \   / \   / \   / \   / \r\n" );
document.write( "         0    -4    -8   -12 \r\n" );
document.write( "          \   / \   / \   /\r\n" );
document.write( "           -4    -4    -4\r\n" );
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\n" ); document.write( "\n" ); document.write( "The differences become common at the 2nd level down, hence the desired model for the nth term is going to be a 2nd degree polynomial.\r
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\n" ); document.write( "\n" ); document.write( "The value of the term when n = 1 is 6, so:\r
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\n" ); document.write( "\n" ); document.write( "Using similar logic, we develop:\r
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\n" ); document.write( "\n" ); document.write( "Solve the 3X3 system to find the values of the coefficients for \r
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\n" ); document.write( "\n" ); document.write( "John
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\"The

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