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+a b`(iv) `a*b=(a-b)^2`(v) `a*b=(a b)/4`(vi) `a*b=a b^2`Find which of the binary operations are commutative and which are associative