Cynthia was offered two different jobs for the summer. Working as a camp counselor, she will earn $10 per hour plus an additional $50 bonus. Her earnings after x hours can be represented by the function f(x) = 10x + 50. Working as a lifeguard, Cynthia will earn $15 per hour and an additional $25 bonus. Her earnings after x hours can be represented by the function g(x) = 15x + 25. The arithmetic operation (f − g)x can be used to determine the difference in the salary Cynthia will earn working as a camp counselor instead of a lifeguard after x hours. What is the function (f − g)x?