
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
The box office revenue of the movie "Battle of Changjin Lake" grew at a constant rate of $x$ every day after the first day. If the revenue after the first day was 3 billion yuan, and the total revenue after 3 days was 10 billion yuan, write the equation to represent this situation.

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