1) 2 целые 1/6 : (8 целых 3\4 - 5 целых 1\2) 2) 3 целых 17\20 : (3целых 2\5 + 1 целая 11\15 25

1) 2.1/6:(8.3/4-5.1/2) = 13/6:(3.1/4) = 13/6:13/4 =4/6=2/3
2) 3.17/20:(3.2/5+1.11/15) = 3.17/20:(3.6/15+1.11/15) = 77/20:4.17/15 = 77/20:77/15 = 15/20 = 3/4 = 0,75