4. Решите уравнение: a) 3 8/9 - x = 1 5/9 ; б) (y - 8 12/19) + 1 7/19 = 6 2/19.

a) 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 б) (y - 8 12/19) + 1 7/19 = 6 2/19 y - 8 12/19 = 6 2/19 - 1 7/19 y - 8 12/19 = 5 + 21/19 - 1 - 7/19 = 4 + 14/19 = 4 14/19 y = 4 14/19 + 8 12/19 y = (4+8) + (14/19 + 12/19) = 12 + 26/19 = 12 + 1 + 7/19 = 13 7/19