To simplify the expression \( 4(x + 5) \) using the Distributive Property, you multiply each term inside the parentheses by 4:
\[ 4(x + 5) = 4 \cdot x + 4 \cdot 5 \]
Calculating that gives:
\[ 4x + 20 \]
So the simplified expression is:
\[ 4x + 20 \]