An Indy race car driver makes a pit stop at the beginning of a lap. The time t in seconds that it takes the driver to complete the lap, including the pit stop, can be modeled by t(x) = 12x+9000 / x where x is the driver’s average speed in miles per hour after the pit stop. The driver’s average speed after the pit stop is 210 mi/h. How long does it take the driver to complete the lap, including the pit stop?

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