Groups and FieldsSuperchallengeCosets and Lagrange's Theorem ShareCosets and Lagrange's Theorem · Superchallenge problemWhat is the smallest k≥1k\ge1k≥1 such that ak≡1(mod561)a^k\equiv1\pmod{561}ak≡1(mod561) for every aaa coprime to 561=3⋅11⋅17561=3\cdot11\cdot17561=3⋅11⋅17?Check Show answer Walk through it step by step Practice more like this Review this concept