To simplify the expression you've provided, let's first rewrite it for clarity:

\[
\frac{5^{10} \cdot 7^{-25} \cdot 5^{4.9} \cdot 49^2}{(125.7)^3} + \frac{5^{9} \cdot 14^{3} \cdot 5^{10} \cdot 7^{-25} \cdot 5^{4.9} \cdot 49^2}{(125.7)^3} + 5^{9} \cdot 14^{3}
\]

### Step 1: Simplifying Terms

1. **Simplify \( 49^2 \)**:
\[
49 = 7^2 \implies 49^2 = (7^2)^2 = 7^4
\]

2. **Combine Terms in the Numerator**:
Let’s focus initially on the numerators of both fractions.

In the first term:
\[
5^{10} \cdot 7^{-25} \cdot 5^{4.9} \cdot 7^4 = 5^{10+4.9} \cdot 7^{-25 + 4} = 5^{14.9} \cdot 7^{-21}
\]

In the second term:
\[
5^{9} \cdot 14^{3} \cdot 5^{10} \cdot 7^{-25} \cdot 5^{4.9} \cdot 7^4 = 5^{9 + 10 + 4.9} \cdot 7^{-25 + 4} \cdot 14^{3} = 5^{23.9} \cdot 7^{-21} \cdot 14^{3}
\]

3. **Combine the Entire Expression**:
The first two fractions can be combined since they have a common denominator:
\[
\frac{5^{14.9} \cdot 7^{-21} + 5^{23.9} \cdot 7^{-21} \cdot 14^{3}}{(125.7)^3}
\]
Factor out \( 7^{-21} \):
\[
= \frac{7^{-21}(5^{14.9} + 5^{23.9} \cdot 14^{3})}{(125.7)^3}
\]

### Step 2: Final Expression Including Third Term
The third term:
\[
5^{9} \cdot 14^{3}
\]

Combining everything into a single expression:
\[
\frac{7^{-21}(5^{14.9} + 5^{23.9} \cdot 14^{3})}{(125.7)^3} + 5^{9} \cdot 14^{3}
\]

### Conclusion
The expression can be kept in this combined form or simplified further depending on the values of the variables. If you need a numerical result or plugging it into a calculator, you'll need to evaluate the specific numbers. If you want only the algebraic re-arrangement or another aspect, please let me know!