Original sentence: The rules are identical to those used for combining resistances, although they require some familiarity with complex numbers.The total impedance of any network of components can be calculated using the rules for combining impedances in series and parallel
Edited sentence: In the general case however, equivalent impedance transforms in addition to series and parallel will be required.The rules are identical to those used for combining resistances, except that the numbers in general will be complex numbers.The total impedance of many simple networks of components can be calculated using the rules for combining impedances in series and parallel