(i)
Given sets are,
U={ 1,2,3,4,5,6,7,8,9 } A={ 2,4,6,8 } B={ 2,3,5,7 } .
A∪B={ 2,3,4,5,6,7,8 } .
Therefore, ( A∪B ) ′ ={ 1,9 } .
A'={ 1,3,5,7,9 } .
B ′ ={ 1,4,6,8,9 } .
Therefore,
A ′ ∩ B ′ ={ 1,3,5,7,9 }∩{ 1,4,6,8,9 } ={ 1,9 } .
Hence, ( A∪B ) ′ = A ′ ∩ B ′ is verified.
(ii)
A∩B={ 2,4,6,8 }∩{ 2,3,5,7 } ={ 2 } .
Therefore,
( A∩B ) ′ =U−( A∩B ) ={ 1,2,3,4,5,6,7,8,9 }−{ 2 } ={ 1,3,4,5,6,7,8,9 } .
Now,
A ′ ={ 1,3,5,7,9 } and B ′ ={ 1,4,6,8,9 } .
Therefore, A ′ ∪ B ′ ={ 1,3,4,5,6,7,8,9 } .
Hence, ( A∩B ) ′ = A ′ ∪ B ′ is verified.