Show that for every prime p, (p - 1) ! = p - 1(mod p) . (you may use exercise 4.) 6. show that for every prime p,(p - 2) ! = 1 (mod p) . (you may use exercise 4 and exercise 5.)
a) 0 (mod p)
b) 1 (mod p
c) p - 1 (mod p)
d) p (mod p)