(2 3/9 - 1 7/9)+ 6 4/9 -(4 2/9+8/9) = решите по действиям нужно

(2 3/9 - 1 7/9)+ 6 4/9 -(4 2/9+8/9) = 1 8/9
1. 2 3/9 - 1 7/9 = 1 12/9 - 1 7/9 = 5/9
2. 4 2/9 + 8/9 = 4 10/9 = 5 1/9
3. 5/9 + 6 4/9 = 6 9/9 = 7
4. 7 - 5 1/9 = 6 9/9 - 5 1/9 = 1 8/9