Пошаговое объяснение:
11/15 - 2/5 = 11/15 - 2*3/15 = 11/15 - 6/15 = 5/15 = 1/3
13/42 - 3/14 = 13/42 - 3*3/42 = 13/42 - 9/42 = 4/42 = 2/21
4/15 - 1/60 = 4*4/60 - 1/60 = 16/60 - 1/60 = 15/60 = 1/4
11/19 - 43/76 = 11*4/76 - 43/76 = 44/76 - 43/76 = 1/76
