The equation \(5x + 3 = x \cdot 5 + 3\) can be analyzed by substituting \(x = 1\):
- Substituting \(x = 1\) into the left side: \(5(1) + 3 = 5 + 3 = 8\).
- Substituting \(x = 1\) into the right side: \(1 \cdot 5 + 3 = 5 + 3 = 8\).
Both sides equal 8, verifying that the equation holds true for \(x = 1\).
This equation demonstrates the Commutative Property of Multiplication because it shows that the order of multiplication does not affect the result (\(5x = x \cdot 5\)).
Therefore, the correct answer is:
The Commutative Property of Multiplication.