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# geometric progression problem (c2) really quickkkk! watch

1. the first three terms of a geometric series are p(3q+1), p(2q+2), p(2q-1). Use algebra to show that one value of q is 5, and find the other possible value of q.

im struggling with this

i never get the right answers (5 and -0.5)
2. a, ar^2, ar^3......

notice that if you take any term of the sequence, say ar^3 and divide it by the previous term, ar^2 you get the common ratio.
3. Be aware that the book's answers are incorrect; suppose q = 5, then the first three terms are 16p, 11p and 9p, which are clearly not in geometric progression.
4. (Original post by GHOSH-5)
Be aware that the book's answers are incorrect; suppose q = 5, then the first three terms are 16p, 11p and 9p, which are clearly not in geometric progression.
does it work if p=5?
5. (Original post by jumblebumble)
does it work if p=5?
The choice of p does not affect whether the sequence is geometric. It can work if p = 5, but it could work for any value of p, without any further knowledge.

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Updated: October 12, 2009
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