
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 that (-1), a1, a2, 8 form an arithmetic sequence, and -1, b1, b2, b3, -4 form a geometric sequence, find the value of a1a2/b2.

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