Equality is symmetric. If lhs = rhs then rhs = lhs. x ≠ 5 means exactly that, x is anything that is not 5. So if you are talking about the natural numbers, x co

Equality is symmetric. If lhs = rhs then rhs = lhs. x ≠ 5 means exactly that, x is anything that is not 5. So if you are talking about the natural numbers, x could be any element of the set {0, 1, 2, 3, 4, 6, 7, ...}. If x = ±5 then x could be any element of the set {-5, 5}.