Adam earns a base pay plus a commission for each car he sells at Crazy Carl's Cool Cars. His monthly salary is modeled by the function f(c) = 250c + 500. If Adam doesn't sell a car, how much money does he earn for the month?

if assume c is commission,and monthly salary function is f(c)=250c+500, so if he doesn't sell anything in month he earn f(0)=250(0)+500=500