Prove directly if the statements that are true, give counterexamples to disprove those that are false. (a). “V k, m,n E Z*, if k? = m² (mod n), then k = m (mod n)." (b). “V m,n E Z*, if m > 2 and n> 2...

Prove directly if the statements that are true, give counterexamples to disprove those that are false. (24 points, 12 each)
(a). “∀ ?,?,?∈ℤ+, if ?2≡?2 (??? ?), then ?≡? (??? ?).”
(b). “∀ ?,? ∈ ℤ+, if ?>2 and ?>2 are prime, then ?4+?4 must be composite.” (Screenshot included)

2 and n> 2 are prime, then m* + n* must be composite." "/>
Extracted text: Prove directly if the statements that are true, give counterexamples to disprove those that are false. (a). “V k, m,n E Z*, if k? = m² (mod n), then k = m (mod n)." (b). “V m,n E Z*, if m > 2 and n> 2 are prime, then m* + n* must be composite."