Question: Solve for $q$ in terms of $p$ and $r$.
r = -qp
q =
1. **State the problem:** We need to solve for $q$ in the equation $$r = -qp$$.
2. **Write the formula and isolate $q$:** The equation is $$r = -qp$$. To solve for $q$, we want to isolate $q$ on one side.
3. **Divide both sides by $-p$:**
$$q = \frac{r}{-p}$$
4. **Simplify the expression:**
$$q = -\frac{r}{p}$$
5. **Explanation:** Dividing both sides by $-p$ cancels the $-p$ multiplying $q$, leaving $q$ alone. The negative sign moves to the numerator.
**Final answer:**
$$q = -\frac{r}{p}$$