1) 5 1/5 : 39/40 = 26/5 : 39/40 = 26/5 * 40/39 = 2/1 * 8/3 = 16/3
2) 2 4/5 : 7/10 = 14/5 : 7/10 = 14/5 * 10/7 = 2/1 * 2/1 = 4
3) 4 * 3/4 = 3
4) 16/3 : 3 = 16/3 * 1/3 = 16/9 - первая дробь
5) 2 - 1 3/20 = 2 - 23/20 = 40/20 - 23/20 = 17/20
6) 17/20 * 48 = 17/5 * 12 = 204/5
7) 1/4 * 20 = 5
8) 5 + 1/10 = 50/10 + 1/10 = 51/10
9) 204/5 : 51/10 = 204/5 * 10/51 = 4/5 * 10/1 = 8 - вторая дробь
10) 16/9 + 8 = 16/9 + 72/9 = 88/9 = 9 7/9
Ответ: 9 7/9