The results for each expression are:
- \( \sqrt{x + 9} \)
- \( \sqrt[3]{64} \approx 4 \)
- \( \sqrt[4]{x^3 + y^2} \)
- \( \sqrt[5]{\frac{3}{5}} \approx 0.9029 \)
Thus, the final boxed answers are:
\[
\boxed{\sqrt{x + 9}, \quad 4, \quad (x^3 + y^2)^{0.25}, \quad 0.9029}
\]