What was the three-fifths compromise? why did it satisfy states in the north and the south?

It satisfied the north because the southerners had to pay taxes for the slaves they had.

it satisfied the south because they didn't have to pay as much money as counting a whole slave

Assemblies do not have written codes of laws. laws are matters for magistrates and courts, not assemblies. codes of law are things such as civil law, criminal law, and constitutional law. what assemblies have are procedures regarding debating, voting and other business they might carry out.  also note that rome had three assemblies: the assembly of the soldiers, the assembly of the tribes, and the plebeian councils.