How do you prove that x equals x?

Answer 1

By the reflexive property of equality, a number is equal to itself: a = a. For example, 2 = 2, 3 = 3, -3/4 = -3/4 etc.

Since x is a variable that represent numbers, then x is equal to itself: x = x.

Suppose that x = x is a false statement.

If x = 1, by the substitution property of equality, 1 can replace x.

So we have 1 = 1 which is a true satement. Therefore, x = x cannot be a false statement. Thus, x = x is true.

If: x = x

Then: x-x = 0