Question

if B is a subset of A, then A=B u (A n B')

Answer 1

I have to show the above

Answer 2

B is subset of A means every B belongs to A also. B' means which are not belongs to B. So B' means universal set - B. B'nA means those belongs to A but not belongs to B. BU(B'nA) means B + elements belogns to A but not belongs to B. => we get A.

Answer 3

we can easily prove by ven diagrams also.