Which areas of authority are held by both state and federal governments?

Concurrent powers are powers that are shared by both the State and the federal government.

explanation:

with the profits from the european sales, merchants purchased europe's manufactured  goods, including tools and weapons. then the merchants shipped those manufactured  goods, along with the  american  sugar and rum, to west africa where they were bartered for  slaves.

well 1 they have there leader that controls them