(2 1/8+7//9-3/9)= (3 2/7+5//13-1/13)= 5 /712+3 3/12-1 1/12= 18*6/8*27= 24*22*25/50*72*11= 29*13+29*2/58*30= 9*32-32*6/16*18= 9/14-(19/35+2/21= 4/25+0,8-2/3= 3/14+(11/63-5/42)=

1. (2 1/8 + 7/8) - (5/9 - 3/9) = 3 - 2/9 = 2 7/9
2. (3 2/7 + 5/7) - (3/13 - 1/13) = 4 - 2/13 = 3 11/13
3. 5 7/12 + 3 3/12 - 1 1/12 = (5 + 3 - 1) + (7/12 + 3/12 - 1/12) = 7 9/12 = 7 3/4
4. 18 * 6/8 * 27 = 108/8 * 27 = 13,5 * 27 = 364,5
5. 24 * 22 * 25/50 * 72 * 11 =  528 * 0,5 * 792 = 264 * 792 =209088
6. 29 * 13 + 29 * 2/58 * 30 = 377 + 29 * 1/29 * 30 = 377 + 1 * 30 = 407
7. 9 * 32 - 32 * 6/16 * 18 = 288 - 2 * 6/1 * 18 = 288 - 216 = 72
8. 9/14 - (19/35 + 2/21) = 135/210 - (114/210 + 20/210) = 135/210 - 134/2 = 1/210
 9. 4/25 +0,8 - 2/3 = 4/25 + 4/5 - 2/3 = 12/75 + 60/75 - 50/75 = 22/75
10. 3/14 + (11/63 - 5/42) =  27/126 + 22/126 - 15/126 = 34/126 = 17/63