Which of the following must be equal to zero for all real numbers x ?
I. −1x−1x
II. x + (-x)
III. x^0 Choose the correct choice from the following answers:
A) I only
B) II only
C) I and III only
D) II and III only
E) I, II , and III
I. -1/x will not be 0 for any real number; The value will be undefined if x is 0;   II. The value will be 0 for any real number. (ex.,) 2 + (-2) = 2-2= 
<gadget id="calculator">2-2</gadget>
<output>0</output>
0;   III. x^0= 1 for real numbers;   II only.   Ans is (II only)
<result>B</result>
Which of the following must be equal to zero for all real numbers x ?
I. −1x−1x
II. x + (-x)
III. x^0