document.write( "Question 1164687: NEED HELP
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document.write( "How do I make a formula for an increasingly decreasing sequence?
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document.write( "eg: 50,49,47,44,40,35,...
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document.write( "and how do I find the next three terms of the sequence? \n" );
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Algebra.Com's Answer #789105 by Theo(13342)![]() ![]() You can put this solution on YOUR website! i found what seems to work.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "formula would be An = A1 - sum of (i - 1) for i = 1 to n.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "formula would work like this:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 1, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A1 = 50 minus sum of (i - 1) for i = 1 to 1 which becomes: \n" ); document.write( "A1 = 50 minus 0 which becomes: \n" ); document.write( "A1 = 50\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 2, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A2 = 50 minus sum of (i - 1) for i = 1 to 2 which becomes: \n" ); document.write( "A2 = 50 minus 0 minus 1 which becomes: \n" ); document.write( "A2 = 50 minus 1 which becomes: \n" ); document.write( "A2 = 49\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 3, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A3 = 50 minus sum of (i - 1) for i = 1 to 3 which becomes: \n" ); document.write( "A3 = 50 minus 0 minus 1 minus 2 which becomes: \n" ); document.write( "A3 = 50 minus 3 which becomes: \n" ); document.write( "A3 = 47\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 4, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A4 = 50 minus sum of (i - 1) for i = 1 to 4 which becomes: \n" ); document.write( "A4 = 50 minus 0 minus 1 minus 2 minus 3 which becomes: \n" ); document.write( "A4 = 50 minus 6 which becomes: \n" ); document.write( "A4 = 44\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 5, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A5 = 50 minus sum of (i - 1) for i = 1 to 5 which becomes: \n" ); document.write( "A5 = 50 minus sum of 0 minus 1 minus 2 minus 3 minus 4 which becomes: \n" ); document.write( "A5 = 50 minus 10 which becomes: \n" ); document.write( "A5 = 40\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 6, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A6 = 50 minus sum of (i = 1) for i = 1 to 6 which becomes: \n" ); document.write( "A6 = 50 minus 0 minus 1 minus 2 minus 3 minus 4 minus 5 which becomes: \n" ); document.write( "A6 = 50 minus 15 which becomes: \n" ); document.write( "A6 = 50 - 15 which becomes: \n" ); document.write( "A6 = 35\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can see that this formula gets you the number you are looking for, which are: \n" ); document.write( "A1 = 50 \n" ); document.write( "A2 = 49 \n" ); document.write( "A3 = 47 \n" ); document.write( "A4 = 44 \n" ); document.write( "A5 = 40 \n" ); document.write( "A6 = 35\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "finding the next 3 terms in the sequence is simply applying the formula.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 7, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A7 = 50 minus sum of (i - 1) for i = 1 to 7 which becomes: \n" ); document.write( "A7 = 50 minus 0 minus 1 minus 2 minus 3 minus 4 minus 5 minus 6 which becomes: \n" ); document.write( "A7 = 50 minus 21 which becomes: \n" ); document.write( "A7 = 29\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 8, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A8 = 50 minus sum of (i - 1) for i = 1 to 8 which becomes: \n" ); document.write( "A8 = 50 minus 0 minus 1 minus 2 minus 3 minus 4 minus 5 minus 6 minus 7 which becomes: \n" ); document.write( "A8 = 50 minus 28 which becomes: \n" ); document.write( "A8 = 22\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when n = 9, An = A1 - sum of (i - 1) for i = 1 to n becomes: \n" ); document.write( "A9 = 50 minus sum of (i - 1) for i = 1 to 9 which becomes: \n" ); document.write( "A9 = 50 minus 0 minus 1 minus 2 minus 3 minus 4 minus 5 minus 6 minus 7 minus 8 which becomes: \n" ); document.write( "A9 = 50 minus 36 which becomes: \n" ); document.write( "A9 = 14\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "to confirm the formula gave you the correct answer, you could do the following.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you are always subtracting 1 more from the previous number than you subtracted from the number preceding that.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "50 minus 0 = 50 for n = 1 \n" ); document.write( "50 minus 1 = 49 for n = 2 \n" ); document.write( "49 minus 2 = 47 for n = 3 \n" ); document.write( "47 minus 3 = 44 for n = 4 \n" ); document.write( "44 minus 4 = 40 for n = 5 \n" ); document.write( "40 minus 5 = 35 for n = 6 \n" ); document.write( "35 minus 6 = 29 for n = 7 \n" ); document.write( "29 minus 7 = 22 for n = 8 \n" ); document.write( "22 minus 8 = 14 for n = 9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the formula here appears to be A.n+1 = A.n - (n-1) \n" ); document.write( "you would start this sequence A1. \n" ); document.write( "from there the formula would get you. \n" ); document.write( "A2 = 50 - 1 = 49 \n" ); document.write( "A3 = 49 - 2 = 47 \n" ); document.write( "A4 = 47 - 3 = 44 \n" ); document.write( "A5 = 44 - 4 = 40 \n" ); document.write( "A6 = 40 - 5 = 35 \n" ); document.write( "A7 = 35 - 6 = 29 \n" ); document.write( "A8 = 29 - 7 = 22 \n" ); document.write( "A9 = 22 - 8 = 14\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "either way, you can see that A7 will be 29 andA8 will be 22 and A9 will be 14.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); 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