SOLUTION: The sum of the first 8 terms of a geometrical series is 17 times the sum of its first 4 terms. Find the common ratio. This is the equation I have come up with (a is first term,

Question 1146283: The sum of the first 8 terms of a geometrical series is 17 times the sum of its first 4 terms. Find the common ratio.
This is the equation I have come up with (a is first term, r is common ratio):

But I don't really know how to solve it.
Answer by greenestamps(13200) (Show Source): You can put this solution on YOUR website!

In your equation, the "a" in the numerator and the "r-1" in the denominator are the same, so the equation simplifies to

Then on the left note that

That should lead you quickly to TWO solutions to the problem.
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