Evaluate the following integrals:
\[
\int \frac{(x^4 + 1)}{x(2x + 1)^2} \, dx
\]
and
\[
\int \frac{1}{x^4 + 5x^2 + 6} \, dx
\]
Show Hint
When dealing with integrals of rational functions, look for opportunities to simplify and split into manageable parts, and use substitution when applicable.