

Mitvoths Bnai Noachide that were repeated in the Ten Commandments
Mitvoths Bnai Noach that were repeated in the Ten Commandments
The Seven Noachide Laws that were given to Moshe with the Ten Commandments, are enumerated separately from the 613 commandments, and are distinct from them in many fundamental ways and aspects.
...The Baal HaTurim (Shemos 20:13) wrote that the 620 letters of the ten commandments correspond to the 613 Mitvoths and the 7 Mitvoths Bnai Noach, and he asks that behold the 7 Mivoths Bnai Noach, Avodah Zarah and Illicit Relations etc. were already included in the 613 commandments.
The Answer: it would have been possible to offer several explanations for this, however in truth there is really no question/difficulty in the first place since also in the 613 Mitvoths the intention is not 613 various general categories, rather the particular inyanim/matters are also taken into consideration if they contain a particular commandment, for example the laws of Avodah Zarah (idolotry) that contain within them several positive commandments/Mitvoths and negative commandments and each one of them is considered to be part of the enumeration of the 613 Mitvoths (the definitions for this are explained in the Sefer HaMivoths by the Rambam - shoresh 9 - and the commentaries there). And how much the more so with regards to the Seven Mitvoths Bnai Noach that contain specific commandents and with fundamental distinctions from the 613 Mitvoths of the Bnai Israel - that are enumerated independently...
(Kol Baie Olam p. 18. quoting Likutei Sichos 2:670)