
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 $ \alpha, \beta \in \left(\frac{\pi}{2}, \pi\right) $ and $ \cos\alpha = -\frac{4}{5}, \sin\beta = \frac{5}{13} $,  
(1) Find the values of $ \sin(\alpha + \beta) $ and $ \cos(\alpha - \beta) $;  
(2) Find the value of $ \tan(2\alpha - \beta) $.

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