The Total solution for NCERT class 6-12
If the binary operation o is defined by a0b = a + b – ab on the set Q –{-1} of all rational numbers other than 1, show that o is commutative on Q –[1].
Let a, b ∈ Q – {-1}.
Then aob = a + b – ab
= b+ a – ba
= boa
Therefore,
aob = boa for all a, b∈ Q – {-1}
Thus, o is commutativeon Q – {-1}