Let-a-b-and-c-be-positive-integers-such-that-ab-1-bc-1-and-bc-1-ca-1-Show-that-ab-1-is-the-sum-of-two-squares-

Question Number 110688 by Aina Samuel Temidayo last updated on 30/Aug/20

Let a, b and c be positive integers such

that ab + 1 ∣ bc + 1 and bc + 1 ∣ ca + 1 .

Show that ab + 1 is the sum of two

squares .