To solve the equation \( 2(x + 2) = 42 \), follow these steps:
1. Distribute the 2 on the left side:
\[
2x + 4 = 42
\]
2. Subtract 4 from both sides to isolate the term with \( x \):
\[
2x = 42 - 4
\]
\[
2x = 38
\]
3. Divide both sides by 2 to solve for \( x \):
\[
x = \frac{38}{2}
\]
\[
x = 19
\]
Thus, the missing value is \( \boxed{19} \).