1. **State the problem:** Simplify the expression $1 - p + 0p - 4p + 4 - 5p$. 2. **Identify like terms:** The terms involving $p$ are $-p$, $0p$, $-4p$, and $-5p$. The constant terms are $1$ and $4$. 3. **Combine like terms:** - Combine the $p$ terms: $-p + 0p - 4p - 5p = (-1 + 0 - 4 - 5)p = -10p$. - Combine the constants: $1 + 4 = 5$. 4. **Write the simplified expression:** $$5 - 10p$$ 5. **Explanation:** We grouped all terms with $p$ together and added their coefficients, then added the constant terms separately. This is a basic algebraic simplification step. **Final answer:** $$5 - 10p$$