
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given the geometric sequence \(\{a_n\}\), \(S_n\) is the sum of the first \(n\) terms. If \(S_5 = 3\) and \(S_{10} = 9\), calculate the value of \(S_{15}\).

Present the answer in LaTex format: \boxed{Your answer}
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