
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 wholesale price of a certain type of shirt is 30 yuan per piece. If the shirt is sold at 40 yuan per piece, 40 pieces can be sold each day. If the price increases by 1 yuan per piece, the number of pieces sold per day will decrease by one. Given this information, find the function that describes the daily net revenue $y$ (in yuan) in terms of the selling price per piece $x$ (in yuan) where $x \geqslant 40$.

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