Question: Find a such that CD has the given slope, $m$. C$(-3, -2)$, D$(1, a)$; $m = 2$
1. **State the problem:** We need to find the value of $a$ such that the slope of the line segment $CD$ is $2$, given points $C(-3, -2)$ and $D(1, a)$.
2. **Recall the slope formula:** The slope $m$ between two points $(x_1, y_1)$ and $(x_2, y_2)$ is given by
$$m = \frac{y_2 - y_1}{x_2 - x_1}$$
3. **Apply the formula to points $C$ and $D$:**
$$2 = \frac{a - (-2)}{1 - (-3)} = \frac{a + 2}{1 + 3} = \frac{a + 2}{4}$$
4. **Solve for $a$:**
Multiply both sides by $4$ to isolate $a + 2$:
$$4 \times 2 = a + 2$$
$$8 = a + 2$$
5. **Subtract $2$ from both sides:**
$$8 - 2 = a$$
$$6 = a$$
**Final answer:**
$$a = 6$$