Ответ: (2,8 + 2 1/3)/2 = 2 17/302 8/10 + 2 1/3 = 2 24/30 + 2 10/30 = 4 34/30 = 5 4/30 = 5 2/15.5 2/15 : 2 = 77/15 × 1/2 = 77/30 = 2 17/30.