Let S be the set of all rational numbers except 1 and * be defined on S by a * b = a + b - ab, for all a, b ∈ S. Prove that: (i) * is a binary operation on S (ii) * is commutative as well as associative. [CBSE 2014]
For each binary operation ∗ defined below, determine whether ∗ is binary, commutative or associative. (iv) On Z+, define a∗b=2ab