Let a,b,c be natural numbers such that a+b+c=2pq(p30+q30),p>q being two given positive integers.
(a) Prove that k=a3+b3+c3 is not a prime number.
(b) Prove that if a⋅b⋅c is maximum, then 1984 divides k. modular arithmeticnumber theorynumber theory unsolved