1. **State the problem:** Simplify the expanded form of $(x - 4y)^5$. 2. **Recall the expanded form:** $$(x - 4y)^5 = x^5 - 20x^4y + 160x^3y^2 - 640x^2y^3 + 1280xy^4 - 1024y^5$$ 3. **Check for like terms:** There are no like terms to combine because each term has different powers of $x$ and $y$. 4. **Conclusion:** The expression is already simplified as much as possible. **Final simplified expression:** $$\boxed{x^5 - 20x^4y + 160x^3y^2 - 640x^2y^3 + 1280xy^4 - 1024y^5}$$