To simplify this expression, we will follow the order of operations (PEMDAS):

Solve inside the parentheses first:
28.5 - 34.125 = -5.625

Simplify the expression further:
2√9 + 16 + 1/224 - (-5.625)√125 + 81
2(3) + 16 + 1/224 - (-5.625)5√(5^2) + 81
6 + 16 + 12 - (-5.625)55 + 81
6 + 16 + 12 + 28.125 + 81
50 + 28.125
78.125

Therefore, 2√9 + 16 + 1/224 - (28.5 - 34.125)√125 + 81 simplifies to 78.125.