
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
In the arithmetic sequence {a<sub>n</sub>}, it is known that a<sub>3</sub> = 10 and a<sub>12</sub> = 31.
1. Find a<sub>1</sub>, d, and the general term formula a<sub>n</sub>.
2. Are 45 and 85 terms in this sequence? If not, explain why. If so, find their respective positions.

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