Total expenditures in a country (in billions of dollars) are increasing at a rate of f(x) = 9.46x + 87.26, where x = 0 corresponds to the year 2000. Total expenditures were $1587.64 billion in 2002. a. Find a function that gives the total expenditures x years after 2000. b. What will total expenditures be in 2013? . . . . . a. What is the function for the total expenditures? F(x ) = (Simplify your answer. Use integers or decimals for any numbers in the expression.) b. In 2013, total expenditures will be $ billion. (Type an integer or a decimal.)