8 and 14 I can do.

8: If a | b, where a and b are positive whole numbers then b = ak for k is some positive whole number: k = 0, 1, 2, 3.... Therefore, a <= b.

14: Since the form of an odd number is 2n + 1 for n = 0, 1, 2...

Let 2a + 1 and 2b + 1 be two odd integers

(2a + 1)(2b + 1) = 4ab + 2a + 2b + 1 = 2(2ab + a + b) + 1 which is an odd integer.