To rewrite the expression \(3(x + 3)\) using the Distributive Property, you multiply 3 by each term inside the parentheses:
\[ 3(x + 3) = 3 \cdot x + 3 \cdot 3 \]
Simplifying this gives:
\[ 3x + 9 \]
So, the expression \(3(x + 3)\) using the Distributive Property is \(3x + 9\).