1. **State the problem:** Solve the equation $X - Y = 0$ for $X$ in terms of $Y$. 2. **Formula and rules:** The equation is a simple linear equation. To isolate $X$, add $Y$ to both sides of the equation. 3. **Intermediate work:** $$X - Y = 0$$ Add $Y$ to both sides: $$X - Y + Y = 0 + Y$$ Simplify: $$X = Y$$ 4. **Explanation:** This means that $X$ is equal to $Y$. For any value of $Y$, $X$ must be the same value to satisfy the equation. **Final answer:** $$X = Y$$