Prove that for all sets A and B BA B ASolutionAssumption i

Prove that for all sets A and B. B-A = B - A.

Assumption is wrong.

I will prove that with help of one example

say A={1,2,3}

B={3,4,5}

then B-A={4,5}...(1)

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A\' will contain {4,5} or even more elements if you consider universal set as all integers but except numbers 1,2,3

then B-A\'={3}...(2)

using (1) and (2) we can clearly see that B-A and B-A\' are not equal .