1. Start with the equation:
xy = yx
2. Verify general conditions for this equation:
- Check for commutative property of multiplication in the set of real numbers:
x \cdot y = y \cdot x
- Since multiplication of real numbers is commutative, the above holds true for any real numbers \( x \) and \( y \).
3. Conclusion:
xy = yx for all values of x and y