优质解答
你的题目抄错了.条件(1)是空集和全集U都要选出,其它没抄错.
解: U= {a,b,c,d}共有16个子集(略).除了空集和全集U,再找两个子集即可.
{a}与{ab},{ac},{ad},{abc},{abd},{acd}.六种.
{b}与{ab}{bc},{bd},{abc},{abd},{bcd}六种.
{c}与{ac},{bc},{cd},{abc},{acd},{bcd}六种
{d}与{ad},{bd},{cd},{abd},{acd},{bcd}六种
{ab}与{abc},{abd}.两种.
{ac}与{abc},{acd}两种.
{ad}与{adb},{adc}两种.
{bc}与{abc},{bcd}两种.
{bd}与{abd},{cbd}两种.
{cd}与{acd},{bcd}两种 所以共36种.
你的题目抄错了.条件(1)是空集和全集U都要选出,其它没抄错.
解: U= {a,b,c,d}共有16个子集(略).除了空集和全集U,再找两个子集即可.
{a}与{ab},{ac},{ad},{abc},{abd},{acd}.六种.
{b}与{ab}{bc},{bd},{abc},{abd},{bcd}六种.
{c}与{ac},{bc},{cd},{abc},{acd},{bcd}六种
{d}与{ad},{bd},{cd},{abd},{acd},{bcd}六种
{ab}与{abc},{abd}.两种.
{ac}与{abc},{acd}两种.
{ad}与{adb},{adc}两种.
{bc}与{abc},{bcd}两种.
{bd}与{abd},{cbd}两种.
{cd}与{acd},{bcd}两种 所以共36种.