1. **Solve for y in the equation** $-10 = \frac{y}{9}$. 2. To isolate $y$, multiply both sides by 9: $$-10 \times 9 = \frac{y}{\cancel{9}} \times \cancel{9}$$ 3. Simplify: $$-90 = y$$ 4. **Final answer:** $y = -90$. This means $y$ is $-90$ when divided by 9 equals $-10$.