A={5,Log2 (a+3)}B={a,b}若A∩B=2则A∪B

问题描述:

A={5,Log2 (a+3)}B={a,b}若A∩B=2则A∪B

A={5,Log2 (a+3) }B={a,b}
若A∩B=2
Log2 (a+3)=2,
a+3=4,a=1,b=2
则A∪B={5,2,1}