A company is setting up offices in two different cities. The number of employees hired by the company for its office in city A over x months is given by the function f(x) = 9x. The number of employees hired by the company for its office in city B over x months is given by the function g(x) = 3(2)x.

Which function best describes the total number of employees in the company over x months, and after how many months will the total number of employees be 141?