To solve the equation \( \frac{x}{4} = 12 \), we need to isolate \( x \). The operation used here is division (since \( x \) is divided by 4), so the inverse operation is multiplication.
We can multiply both sides of the equation by 4 to solve for \( x \):
\[ x = 12 \times 4 \]
Calculating \( 12 \times 4 \):
\[ x = 48 \]
Thus, the correct response is:
Inverse operation is multiplication; x = 48.