To solve these equations, we first need to find common denominators in order to add the fractions together.

For (3/8 - 1/9) + 25/36:
The common denominator is 72.
(27/72 - 8/72) + 25/72 = 19/72 + 25/72 = 44/72 = 11/18

For (8/9 - 5/6) + 2/3:
The common denominator is 18.
(16/18 - 15/18) + 12/18 = 1/18 + 12/18 = 13/18

Therefore, the solutions are:
(3/8 - 1/9) + 25/36 = 11/18
(8/9 - 5/6) + 2/3 = 13/18