Let * be a binary operation on the set Q of rational numbers as follows: (i) a * b = a − b (ii) a * b = a 2 + b 2 (iii) a * b = a + ab (iv) a * b = ( a − b ) 2 (v) (vi) a * b = ab 2 Find which of the binary operations are commutative and which are associative.

Let * be a binary operation on the set Q of rational numbers as foll

1.	Let * be a binary operation on the set Q of rational numbers as follows: (i) a * b = a − b (ii) a * b = a 2 + b 2 (iii) a * b = a + ab (iv) a * b = ( a − b ) 2 (v) (vi) a * b = ab 2 Find which of the binary operations are commutative and which are associative.
Answer» Let * be a binary operation on the set Q of rational numbers as follows: (i) a * b = a − b (ii) a * b = a 2 + b 2 (iii) a * b = a + ab (iv) a * b = ( a − b ) 2 (v) (vi) a * b = ab 2 Find which of the binary operations are commutative and which are associative.