Pls solve and answer the question in detail. Q. If x, y and z are real then the possible value of the expression x 2 + 4 y 2 + 9 z 2 - 6 y z - 3 z x - 2 x y may be. (A) Non negative (B) negative (C) zero (D) Any real no. Share with your friends Share 0 Brijendra Pal answered this Hi, let it is equal to u and then so option a 1 View Full Answer