Q34: The operation Θ is defined by x Θ y = 1/x + 1/y for all nonzero numbers x and y. If z is a number greater than 1, which of the following must be true? I. x Θ (-z) = 0
I. x Θ (-z) = 0 II. z Θ z/(z-1)= 1 III. 2/z Θ 2/z = z A. I only
B. I and II only C. I and III only
D. II and III only
E. I, II, and III 答案是e, 請8有沒有人可解答?especial for 1 and 3. 之前有人問過,但打錯題目, 謝謝 | 
