2 1 15 3 4 m 59 60 July 8, 2019 16 32 64 128 2 1 15 3 4m 59 60 2 1/15-3/4m=59/60 2 1/15-3/4х=59/60 2 1/5-3/4m=59/60 2 15-1 45