Suppose f(x) represents the amount of money in a bank account after x weeks.If you want to represent the amount of money in a bank after 7 weeks, what should you write instead of f(x)?
Since f(x) represents the amount of money in a bank account after x weeks and we want to know the money after 7 weeks we need to plug x=7 in the function, that is we need to write f(7).
