Question

U={2.3.4.5.6.7.9} A={2.4.6} B={3.5.7} hole AB=koto​

Answer 1

A={2,4,6}B={3,5,7}AB={2,4,6}cross{3,5,7}AB={(2,3),(2,5),(2,7),(4,3),(4,5),(4,7),(6,3),(6,5),(6,7)}I ...