Вычислите 2/7 + 3/6 7/8+1/2 2/3·9/20 5/9+1/4 6/7-1/2 14/27·9/49 8/9+1/8 5/9-1/6 31/32·64/93 6/7+1/3 5/18·4/15 29/45+7/15 11/12-3/4 9/10·10/23 5/14+8/21 3/4-4/9 2/3·18 9/10+1/6 7/8-7/12 6/11·22/23 5/7-1/2 9/10·20/27 2/3+4/7 5/7-1/6 11/18·24/55 2/3+2/5 6/7-6/8 4/25·50/44 7/9+2/3 2/3-1/13 7/16+5/24 44/45-7/9 24/65·15/32 15/26+12/13 20/21-3/14 5/42·36/43 5/18+8/27 15/16-3/8 35/51·17/70 7/8+11/12 40