Answer
{}, {4}, {8}, {12}, {4,8}, {4,12}, {8,12}, {4,8,12}
Work Step by Step
Find the subsets with no members: { }
Find the subsets with one member: (4}, {8}, {12}
Find the subsets with two members: {4,8}, {4,12}, {8,12}
Find the subsets with three members: (4,8,12)