True or false

1. for a real number a, a + 0 = a.

2. for a real number a, a + (-a) = 1.

3. for a real numbers a and b, | a - b | = | b - a |.

4. for real numbers a, b, and c, a + (b ∙ c) = (a + b)(a + c).

5. for rational numbers a and b when b ≠ 0, is always a rational number.