Question: 8 - (-12) + 20 - 13 + (-15)
1. **State the problem:** Simplify the expression $$8 - (-12) + 20 - 13 + (-15)$$.
2. **Recall the rule:** Subtracting a negative number is the same as adding its positive counterpart, so $$8 - (-12) = 8 + 12$$.
3. **Rewrite the expression:**
$$8 + 12 + 20 - 13 + (-15)$$
4. **Perform the additions and subtractions step-by-step:**
- $$8 + 12 = 20$$
- $$20 + 20 = 40$$
- $$40 - 13 = 27$$
- $$27 + (-15) = 27 - 15 = 12$$
5. **Final answer:**
$$12$$