1. **Stating the problem:** Calculate the total monthly expenses based on the given amounts for rent, child expenses, car, and phone. 2. **List expenses:** - Rent = 3600 - Child = 1000 - Car and phone combined = 450 3. **Calculate total expenses:** $$\text{Total expenses} = 3600 + 1000 + 450 = 5050$$ 4. **Calculate remaining salary:** $$\text{Remaining salary} = 5400 - 5050 = 350$$ **Final answer:** After paying for rent, child expenses, car, and phone, the remaining salary is $350.