1) 3 1/8 + 2 1/12 = 25/8 [12] + 25/12 [25] = 300/96 + 625/96 = 925/96 = 9 61/96
2) 9 61/96 - 1/3 = 925/96 [1] - 1/3 [32] = 925/96 - 32/96 = 893/96 = 9 29/96
3)0,4 * 8,5 = 3,4
4) 7,3 - 3,4 = 3,9
5) 9 29/96 : 3,9 = 893/96 : 3 9/10 = 893/96 : 39/10= 893 * 10/96*39 = 8930/3744 = 2 1442/3744 = 2 721/1872
Ответ: 2 721/1872