1)3 целых 1/4+2 целых 1/6 : 2 целых 3/5= 3 1/4 + 13/6 : 13/10 = 3 1/4 + 13/6 * 10/13 = 3 1/4 + 10/6 = 13/4 + 10/6 = 39/12 + 20/12 = 59/12 = 4 11/12
2)712 целых : 89 целых+(9 целых 10/21- 5 целых 3/7)= 8 + (9 10/21 - 5 9/21) = 8 + 4 1/21 = 7 21/21 + 4 1/21 = 11 22/21 = 12 1/21
3)7/10:2 целых 1/2+1/3:5/24-22/25= 7/10 : 5/2 + 1/3 : 5/24 - 22/25 = 7/10 * 2/5 + 1/3 * 24/5 - 22/25 = 7/25 + 8/5 - 22/25 = 7/25 + 40/25 - 22/25 = 25/25 = 1