Question

(12 целых 5/13 +y)-9 целых 9/13=7целых 7/13

Answer 1

(12 5/13 + у) - 9 9/13 = 7 7/13
12 5/13 + у = 7 7/13 + 9 9/13
12 5/13 + у = 16 16/13
у = 16 16/13 - 12 5/13
у = 4 11/13
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Проверка: (12 5/13 + 4 11/13) - 9 9/13 = 7 7/13
                   16 16/13 - 9 9/13 = 7 7/13
                   7 7/13 = 7 7/13