True or false for each statement.

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, is always a rational number.