Question

设A={x|x是小于9的正整数},B={1,2,3},c={3,4,5,6},求AnB,Anc,An(BUC),AU(B

Answer 1

1、A交B={1,2,3}

2、A交C={3,4,5,6}

3、A交(B并C）={1,2,3,4,5,6}

4、A并（B交C）={1,2,3,4,5,6,7,8}