To access a object's function you must use a '.' (or a -> for a pointer to an object). ex:
1 2
Account savings;
savings.makeDeposit(savings);
you're defining a function in the main file that has the same name as a function from Account class. This is ok, but you must give the function a body. Please note this isn't needed to access the object's functions.
anyone please correct me if I'm wrong.
if you're trying to use the object's functions to deposit, do this:
lines 53 and 54 shouldn't be there. These function declarations mask the real errors. (They lead the compiler to expect global functions, which is what the linker will be complaining about.)
Which is that, on line 72 and t4, you should be calling you class' methods through an instance with the . (dot) operator. As your instance is called savings, e.g.