5целых2/7-1/3+6; 3целых5/12-4/5+31/60; 8целых-5целых3/4+6 . . всё

5 2/7 - 1/3 + 6 = 37/7 - 1/3 + 6/1 = (111-7+126)/21 = 230/21 = 10 20/21
3 5/12 - 4/5 + 31/60 = 41/12 - 4/5 + 31/60 = (205-48+31)/60 = 188/60 = 3 8/60 = 3 2/15
8 - 5 3/4 + 6 = 2 1/4 + 6 = 8 1/4