123. Упростите выражение:

a) (3y + 4/5y - 5/12y) = (36/60y + 48/60y - 25/60y) = (59/60y). b) (5/18m + 2 7/12m - 1 2/9m) = (5/18m + 33/12m - 11/9m) = (50/18m + 49/18m - 22/18m) = (77/18m).