29 13/51-12 23/57+11 4/51+3 4/57 как решить

(29)13/51 - (12)23/57 + (11)4/51+ (3)4/57 = [(29)13/51 + (11)4/51] -- [(12)23/57 - (3)4/57] = (40)17/51 - (9)19/57 = (40)1/3 - (9)1/3 = 31