Often to pay back debt, a government will do two things. One, they will cut back on the amount of money they

spend. Two, they will raise taxes. Based on your understanding of the estates system, if the king raised taxes in 1789,

who would have to pay them?

The estate system was a form of social hierarchy where peasants (lower class citizens) worked in a land owned by someone of the noble class. In return of their work, the noble would provide them protection for any enemy; or any other service previously agreed. This was also called feudalism. In this example, if the king raised the taxes in 1789, the people who would need to pay them were the peasants, since they worked for the government and didn't have any power or vote against it.