SOLUTION: 2;x;y are the first 3 terms of an arithmetic sequence . If each term is decreased by 1, the resulting sequence is geometric. Determine the two sequences.

Algebra ->  Sequences-and-series -> SOLUTION: 2;x;y are the first 3 terms of an arithmetic sequence . If each term is decreased by 1, the resulting sequence is geometric. Determine the two sequences.      Log On


   



Question 842117: 2;x;y are the first 3 terms of an arithmetic sequence . If each term is decreased by 1, the resulting sequence is geometric. Determine the two sequences.
Answer by richwmiller(17219) About Me  (Show Source):
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an = a + (n - 1)d
2=a
x = 2 + d
y = 2 + 2d
Geometric
1=t
x-1 = r,
y-1 = r^2,
x = 2 + d,
y = 2 + 2d
answer:
d = 0, r = 1, x = 2, y = 2
arithmetic
2,2,2
geometric
1,1,1