The denominator of the expression \( \frac{y^{2}+y-14}{y^{2}-49}+\frac{2}{y+7} \) is \( y^{2} - 49 \). This can be factored as:
\[
y^{2} - 49 = (y - 7)(y + 7)
\]
Thus, the factorized form of the denominator is \( (y - 7)(y + 7) \).
Step 2: Combine the Fractions
We can rewrite the expression using the factorized form:
\[
\frac{y^{2} + y - 14}{(y - 7)(y + 7)} + \frac{2}{y + 7}
\]
To combine these fractions, we need a common denominator:
\[
\frac{y^{2} + y - 14 + 2(y - 7)}{(y - 7)(y + 7)}
\]
Simplifying the numerator:
\[
y^{2} + y - 14 + 2y - 14 = y^{2} + 3y - 28
\]
Thus, the combined expression is:
\[
\frac{y^{2} + 3y - 28}{(y - 7)(y + 7)}
\]
Step 3: Perform Partial Fraction Decomposition
Next, we perform partial fraction decomposition on the expression:
\[
\frac{y^{2} + 3y - 28}{(y - 7)(y + 7)}
\]
This can be expressed as:
\[
\frac{A}{y - 7} + \frac{B}{y + 7}
\]
After performing the decomposition, we find:
\[
\frac{y - 4}{y - 7}
\]
Final Answer
The final result of the expression \( \frac{y^{2}+y-14}{y^{2}-49}+\frac{2}{y+7} \) after simplification and partial fraction decomposition is:
\[
\boxed{\frac{y - 4}{y - 7}}
\]