Не как не : 3/4: 5/6+2 целых 1/2*2/5-1 целая: 1 целая 1/6 ответ

1 вариант:
3/4 : 5/6 + 2 1/2 * 2/5 - 1: 1 1/6 = 3*3/4*3 : 5*2/6*2 + 5/2 * 2/5 - 6/6 : 7/6 =
= 9/12 : 10/12 + 5*2/2*5 - 6/6 * 6/7 = 9*12/12*10 + 10/10 - 36/42 =
= 108/120 + 1 - 18/21 = 27/30 + 1 - 1 6/7 =9/10 + 1 - 6/7 =
= 9*7/10*7 + 70/70 - 6*10/7*10 = 63/70 + 70/70 - 60/70 = (63+70-60)/70 = 73/70 = 1 3/70

2 вариант:
3/4 : 5/6 + 2 1/2 * 2/5 - 1: 1 1/6 = 3*6/4*5 + 5/2 * 2/5 - 1 : 7/6 = 18/20 + 10/10 - 1 * 6/7 = 18/20 + 1 - 6/7 = 18*7/20/7 +1 - 6*20/7*20 = 126/140 + 1 - 120/140 = 1 6/140 = 1 3/70