SOLUTION: 1) Find the next two terms of the following sequence: -21,-9,11,39,... 2) Use the explicit formula, An=(-1)^n(13n-6), to find the first five terms of the sequence.

Algebra ->  Sequences-and-series -> SOLUTION: 1) Find the next two terms of the following sequence: -21,-9,11,39,... 2) Use the explicit formula, An=(-1)^n(13n-6), to find the first five terms of the sequence.      Log On


   

Question 1085415: 1) Find the next two terms of the following sequence: -21,-9,11,39,...
2) Use the explicit formula, An=(-1)^n(13n-6), to find the first five terms of the sequence.
Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
1) The differences for the four terms given are 12,20,28, so I'd say the next two differences are 36 and 44:
39+36 = 75
75+44 = 119
Ans: The next two terms are 75, 119
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2) +A%5B0%5D+=+%28-1%29%5E0%2813%280%29-6%29+=+6+
+A%5B1%5D+=+%28-1%29%5E1%2813%281%29+-+6%29+=+-1%2A7+=+-7+
+A%5B2%5D+=+%28-1%29%5E2%2813%282%29+-+6%29+=+20+
+A%5B3%5D+=+%28-1%29%5E3%2813%283%29+-+6%29+=+-33+
+A%5B4%5D+=+%28-1%29%5E4%2813%284%29+-+6%29+=+46+
etc.