6m 3 2m 7 July 8, 2019 16 32 64 128 6m 3 2m 5 )+ 7 6m 3 7 2m 1 7 5m 3 6m 7 2m 2 6m 7 2m 3 4n 6 3 m 3 6m = - 7 2 6 m 3 m 6 m 7