Why is section 2 an important part of the 13th amendment

Section 2 of the Thirteenth Amendment is called an empowering or enabling clause. Just about all amendments have them. The amendment itself has no detail on how the amendment is to be enforced. Congress passed the Voting Rights Act to define just what "slavery" meant, even though it seems self-evident. Slavery comes in many forms, not just the legal ownership of persons. For example, it
could mean slavery by the use of threats of harm where a person is coerced against his will to be a virtual slave. The amendment did not state the punishment that would be given to persons that continued to keep slaves in spite  of the amendment

11x-7y=121+7y +7y11x=7y+121-121 -121-121+11x=7y(divide each side by 7)y=11/7x-121/7