1. **State the problem:** Simplify the expression $12pr - 8pr - 19$. 2. **Identify like terms:** The terms $12pr$ and $-8pr$ are like terms because they both contain the variables $p$ and $r$. 3. **Combine like terms:** $$12pr - 8pr = (12 - 8)pr = 4pr$$ 4. **Rewrite the expression:** $$4pr - 19$$ 5. **Final answer:** The simplified expression is $4pr - 19$. This expression cannot be simplified further because $4pr$ and $-19$ are not like terms.