A binary operation * is defined on the set of positive integers is such x*y = 2x-3y+2 for all positive integers x and y. The binary operation is
A. commutative and close on the set of positive integers B. neither commutative nor closed on the set of ppositive integers C. commutative but not closed on the set of positive integers D. not cummutative but closed on the set of positive integers
Correct Answer: B
Explanation
X * Y = 2X - 3Y + 2 2*3 = 2(2) - 3(3) + 2 =4-9+2 = -3 But -3 does not belong to positive integer
