Geometric Sequences & Progressions - Exam Question - 3 Consecutive Terms and an Unknown X - Find X

Given 3 consecutive terms of a geometric sequence, 2 of which contain an unknown x, we learn how to find the unknown x.
This is a must-know exam question.
The method / technique is shown, using the formula for the common ratio we set-up an equation for x, which ends-up as a quadratic equation leading to 2 possible values for x.

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