Question

If A = {1, 2, 3, 4, 5 }; B = {4, 5, 6, 7}, then find A – B and B – A. Are they equal?

Answer 1

Given sets are 

A = {1, 2, 3, 4, 5} and B = {4, 5, 6, 7} 

A – B = {1, 2, 3, 4, 5} – {4, 5, 6, 7} = {1, 2, 3} 

B – A = {4, 5, 6, 7} – {1, 2, 3, 4, 5} = {6, 7} 

∴ No, A – B ≠ B – A.