$\"\"$

Number $\"\"$ of cars produced at a certain factory in one day after $\"\"$ hours operation is $\"\"$ Where $\"\"$ .

Cost $\"\"$ of producing $\"\"$ cars is $\"\"$ .

Substitute $\"\"$ in $\"\"$ .

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Cost $\"\"$ as a function of the time $\"\"$ of operation of the factory is $\"\"$ .

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Cost $\"\"$ as a function of the time $\"\"$ of operation of the factory is $\"\"$ .