In mathematica. can someone help me with this please?

(a) Suppose that K = (a, b) is a key in an Affine Cipher over 2m. Prove that K is an involutory key if and only if a-i mod n = a and b(a + 1) 1.1 1 0 (mod n). (b) Determine all the involutory keys in the Affine Cipher over Z1s. (c) Suppose that n pq, where p and q are distinct odd primes. Prove that the number of involutory keys in the Affine Cipher over Zn is n +p+q+1