9(CuA)∩B={4,6,8},中的9是打多的吧
A∩B={3},(CuA)∩B={4,6,8},得B中有{3,4,6,8}
A∩B={3},A∩(CuB)={1,5},得A中有{1,3,5}
(CuA)U(CuB)={x|x