Global Warming The amount of carbon dioxide (in pounds per 15,000 cubic mi...

Global Warming The amount of carbon dioxide (in pounds per 15,000 cubic miles) released by a typical SUV depends on its fuel efficiency according to the formula

where x is the fuel efficiency of an SUV in miles per gallon. According to the model, what is the fuel efficiency of the SUV with the least carbon dioxide pollution? Comment on the reliability of the model for fuel efficiencies that exceed your answer.