I need help with the following:

15. This exercise is about the strange ring A made up of numbers of the form a + by-5 where a, b are integers. Read Section 2.3 of Taste before starting this problem. (a) Show that 41 is not an A-prime. Hint: 41 = 36 + 5. (b) If r E A and N(a) is a prime in Z, show that x is an A-prime. (c) Show that 3 + 2v-5 is an A-prime