Start with the hint you were given: Restate the complex number "z" in it's generic "a + bi" form. Use this to create an expression for the conjugate...
So your class hasn't yet covered this topic, and the terms in the homework exercise have not yet been defined in class? That's... a problem. We need...
Have these topics not yet been covered in class? If not, maybe the lecture, when added to your textbook, will answer your questions. If so, what have...