Пошаговое объяснение:
1) 5/6 + 0,25 = 5/6 + 25/1 00 = 5/6 + 1/4 = 10/12 + 3/12 = 13/12
2) 4. 1/3 : 13/12 = 13/3 * 12/13 = 12/3 = 4
3) 7/12 - 2/15 = 35/60 - 8/60 = 27/60
4) 27/60 : 0,9 = 27/60 : 9/10 =27/60 * 10/9 = 3/6 * 1/1 = 3/6 = 1/2
4) 4 : 1/2 = 4 * 2/1 = 8/1 = 8
5) 7/12 + 1/9 = 21/36 + 4/36 = 25/36
6) 3,6 * 25/36 = 3. 6/10 * 25/36 = 36/10 * 25/36 = 25/10 = 5/2
7) 5/8 - 1/3 = 15/24 - 8/24 = 7/24
8) 7/24 * 1. 5/7 = 7/24 * 12/7 = 12/24 = 1/2
9) 5/2 : 1/2 = 5/2 * 2/1 = 10/2 = 5
10) 8 - 5 = 3
ответ : 3
(x+2целых 9/11)-4 целых10/11=1целых 4/11
(x+2целых 9/11)=4целых 10/11+1 целых4/11
(x+2целых 9/11)=6целых 3|11
х=6 целых3/11-2 целых9/11
х=3 целых5/11