The expression \( 11(b + z) = 11b + 11z \) demonstrates the distributive property of multiplication over addition, not the commutative property.
The commutative property of multiplication states that the order of the factors does not change the product, which can be expressed as:
\[ a \cdot b = b \cdot a \]
For example, \( 11 \cdot (b + z) = (b + z) \cdot 11 \) would illustrate the commutative property.
Therefore, while the given expression is a valid equation involving multiplication and addition, it does not demonstrate the commutative property.