№12. Заполните пустые клетки. а) + (2rac{2}{7}) (3rac{4}{7}) 2 6 (5rac{4}{7}) б) + (3rac{5}{11}) (2rac{6}{11}) (3rac{6}{11}) (1rac{3}{11}) (-rac{5}{11})

а) | + | (2rac{2}{7}) | (3rac{4}{7}) | |---|---|---| | 2 | (4rac{2}{7}) | (5rac{4}{7}) | | 6 | (8rac{2}{7}) | (9rac{4}{7}) | | (5rac{4}{7}) | (8) | (9rac{1}{7}) | б) | + | (3rac{5}{11}) | (2rac{6}{11}) | |---|---|---| | (3rac{6}{11}) | (7rac{1}{11}) | (6rac{1}{11}) | | (1rac{3}{11}) | (4rac{8}{11}) | (3rac{9}{11}) | | (-rac{5}{11}) | (3) | (2rac{1}{11}) |