1. **Stating the problem:** Isabelle needs to complete 20 more practice hours. She drives 4 hours each week for 3 weeks. We want to find expressions that represent the change in her remaining practice hours. 2. **Understanding the problem:** Each week, Isabelle reduces her remaining hours by 4. Over 3 weeks, the total change is 3 times -4 (since the hours remaining decrease). 3. **Formula:** Change in hours = number of weeks \( \times \) change per week 4. **Evaluating each expression:** - a) \(3 \times (-4) = -12\) which correctly represents a decrease of 12 hours. - b) \((-3) \times (-4) = 12\) which is positive, meaning an increase, so incorrect. - c) \((-4) + (-4) + (-4) = -12\) which correctly represents a decrease of 12 hours. - d) \((-4) \times (-4) \times (-4) = -64\) which is not the correct representation of weekly decrease. - e) \((-3) \times (-3) \times (-3) \times (-3) = 81\) which is positive and unrelated to the problem. 5. **Conclusion:** The expressions that represent the change to her remaining practice hours are a) \(3 \times (-4)\) and c) \((-4) + (-4) + (-4)\). **Final answer:** a and c