Question: top-left: 2. $\sum_{j=2}^{6} (j^3 - 1)$
1. **State the problem:** We need to evaluate the sum $$\sum_{j=2}^{6} (j^3 - 1)$$ which means adding the values of $j^3 - 1$ for $j=2,3,4,5,6$.
2. **Formula and rules:** The summation notation $$\sum_{j=a}^{b} f(j)$$ means to calculate $f(j)$ for each integer $j$ from $a$ to $b$ and then add all those values.
3. **Calculate each term:**
- For $j=2$: $2^3 - 1 = 8 - 1 = 7$
- For $j=3$: $3^3 - 1 = 27 - 1 = 26$
- For $j=4$: $4^3 - 1 = 64 - 1 = 63$
- For $j=5$: $5^3 - 1 = 125 - 1 = 124$
- For $j=6$: $6^3 - 1 = 216 - 1 = 215$
4. **Sum all terms:**
$$7 + 26 + 63 + 124 + 215 = 435$$
5. **Final answer:**
$$\sum_{j=2}^{6} (j^3 - 1) = 435$$