问题
填空题
集合A1,A2满足A1∪A2={a,b},则满足条件的集合A1,A2总共有______组.
答案
A1∪A2={a,b}
则A1=∅时,A2={a,b};
A1={a}时,A2={b},A2={a,b};
A1={b}时,A2={a},A2={a,b};
A1={a,b}时,A2={a},A2={b},A2={a,b},A2=∅;
∴A1,A2总共有 9组.
故答案为:9
集合A1,A2满足A1∪A2={a,b},则满足条件的集合A1,A2总共有______组.
A1∪A2={a,b}
则A1=∅时,A2={a,b};
A1={a}时,A2={b},A2={a,b};
A1={b}时,A2={a},A2={a,b};
A1={a,b}时,A2={a},A2={b},A2={a,b},A2=∅;
∴A1,A2总共有 9组.
故答案为:9