
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 {a<sub>n</sub>} is an arithmetic sequence, where a<sub>1</sub> = 25, a<sub>4</sub> = 16
1. From which term does the sequence {a<sub>n</sub>} start to become less than 0?
2. Find the value of a<sub>1</sub> + a<sub>3</sub> + a<sub>5</sub> + ... + a<sub>19</sub>.

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