1. **State the problem:** Simplify the expression $3(-9x - 6y)$. 2. **Formula and rules:** Use the distributive property which states $a(b + c) = ab + ac$. Here, $a=3$, $b=-9x$, and $c=-6y$. 3. **Apply the distributive property:** $$3(-9x - 6y) = 3 \times (-9x) + 3 \times (-6y)$$ 4. **Multiply each term:** $$3 \times (-9x) = -27x$$ $$3 \times (-6y) = -18y$$ 5. **Write the simplified expression:** $$-27x - 18y$$ **Final answer:** $-27x - 18y$