from the beginning of 2000 to the beginning of 2007 the u.s. consumed gasoline at a rate approximated by: billions of gallons per year where t is the number of years since 2000. during the same period, the price of gasoline can be approximated by: dollars per gallon estimate to the nearest $10 billion, the total spent on gasoline in the u.s. from the beginning of 2000 to the beginning of 2007.