
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), a_{1}, a_{2}, (-9) form an arithmetic sequence, and (-9), b_{1}, b_{2}, b_{3}, (-1) form a geometric sequence, find the value of b_{2}(a_{2}-a_{1}).

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