Решите уравнение: (12 целых 5/13+y) - 9 целых 9/13=7 целых7/13

(12 5/13 + у) - 9 9/13 = 7 7/13;

12 5/13 + у - 9 9/13 = 7 7/13;

у = 7 7/13 - 12 5/13 + 9 9/13;

1. 7 7/13 - 12 5/13 = 7 7/13 - 11 18/13 = - 4 11/13;

2. - 4 11/13 + 9 9/13 = - 4 11/13 + 8 22/13 = 4 11/13;

у = 4 11/13;

Проверим решение уравнения.

(12 5/13 + у) - 9 9/13 = 7 7/13;

12 5/13 + 4 11/13 - 9 9/13 = 7 7/13;

1. 12 5/13 + 4 11/13 = 16 16/13 = 17 3/13;

2. 17 3/13 - 9 9/13 = 16 16/13 - 9 9/13 = 7 7/13;

7 7/13 = 7 7/13;

Уравнение решено правильно.