Решаю по действиям
1)4 4/10 - 4 15/100 + 1 7/15 + 7/60 = 24/60-9/60+1 28/60+7/60=1 50/60=1 5/6
2)1 5/6 : 3 2/3 = 11/6 :11/3 = 1/2
3)3 1/2-2 75/100=3 2/4 -2 3/4 = 14/4-11/4 = 3/4
4) 3/4 :2/10 = 30/8 = 15/4 = 3 3/4
5) 3 3/4 - 2 1/2 = 3 3/4 - 2 2/4 = 1 1/4
6) 1/2 :1 1/4 = 1/2 * 4/5 = 2/5