Question

设A≠B，且A,B均为非空集合，求满足A∪B={a1，a2}的集合A，B的一切可能组成情况

Answer 1

1.A={a1},B={a2}
2.A={a2},B={a1}
3.A={a1，a2},B={a1}
4.A={a1，a2}.B={a2}
5.A={a1},B={a1，a2}
6.A={a2}.B={a1，a2}

Answer 2

既然A不等于B，那么5种情况
1.A={a1},B={a2}
2.A={a1，a2},B={a1};
3.A={a1，a2}.B={a2};
4.A={a1},B={a1，a2};
5.A={a2}.B={a1，a2};