If U=(1,2,3,4,5,6,7,8,9)

A=(1,2,3) is A a subset of U and is U a superset of A.

yes A is a SUBSET of U and U is a SUPERSET of A.

Explanation: use curly braces for the elements.

A is a subset of U since U has the elements {1,2,3,4,5,6,7,8,9}, and A has the elements {1,2,3}

U contains the elements listed in set A, so a is a SUBSET of U

Below

Step-by-step explanation:

A is a subset of U because 1,2,3 is in set U.

U is a superset of A as U contains 1,2,3 and other elements.