4. Решите уравнения: а) 3 8/9 - X = 1 5/9; б) (X - 8 12/19) + 1 7/19 = 6 2/19.

* а) 3 8/9 - X = 1 5/9 * X = 3 8/9 - 1 5/9 * X = (3 - 1) + (8/9 - 5/9) * X = 2 + 3/9 * X = 2 1/3 (Сократили 3/9 на 3) * б) (X - 8 12/19) + 1 7/19 = 6 2/19 * X - 8 12/19 = 6 2/19 - 1 7/19 * X - 8 12/19 = 5 - 5/19 * X - 8 12/19 = 4 14/19 * X = 4 14/19 + 8 12/19 * X = 12 + 26/19 * X = 12 + 1 7/19 * X = 13 7/19