Problem Solving

which of the following must be equal to zero for all real numbers x?

I. -1/X

II. X+(-X)

III. X ^0

a - I only

b - II only

c - I and III only

d - II and III only

e - I, II, and III

OG answer is b - can someone please explain what they mean by all real numbers X?

this implies all numbers you have studied so far, unless you were math major in college. From the content of your question I read you aren't math major and unaware of complex number operations, therefore consider this as all numbers you know - fractions, decimals, different sign numbers, absolutely all numbers (except for complex numbers).

factor26 wrote:which of the following must be equal to zero for all real numbers x?

I. -1/X

II. X+(-X)

III. X ^0

a - I only

b - II only

c - I and III only

d - II and III only

e - I, II, and III

OG answer is b - can someone please explain what they mean by all real numbers X?

By all real number, they mean all the numbers that can be represented on the number line.