
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 store normally sells windows at $100 each. This week, the store is offering two free windows for each purchase of six windows. Dave needs nine windows and Doug needs ten windows. Calculate the total cost when they purchase the windows together compared to the sum of the costs when they purchase the windows separately.

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