1. We start with the equation: $$l - b - x - 2 \cdot 25 = x - 50$$ 2. Simplify the multiplication: $$2 \cdot 25 = 50$$ So the equation becomes: $$l - b - x - 50 = x - 50$$ 3. Add 50 to both sides to cancel the -50 on the left: $$l - b - x - 50 + 50 = x - 50 + 50$$ which simplifies to: $$l - b - x = x$$ 4. Add $x$ to both sides to isolate terms: $$l - b - x + x = x + x$$ which simplifies to: $$l - b = 2x$$ 5. Finally, solve for $x$: $$x = \frac{l - b}{2}$$ This means $x$ is half the difference between $l$ and $b$.