11) 12 3/10 - 9/10 = 12 + 3/10 - 9/10 = 12 - 6/10 = 12 - 3/5 = 11 + 1 - 3/5 = 11 + 5/5 - 3/5 = 11 + 2/5 = 11 2/5
Ответ: 11 2/5