To solve the equation \( 12x - 4 = 4(x + 5) \), start by distributing on the right side:
\[ 4(x + 5) = 4x + 20 \]
Now, rewrite the equation:
\[ 12x - 4 = 4x + 20 \]
Next, isolate \( x \) by first subtracting \( 4x \) from both sides:
\[ 12x - 4x - 4 = 20 \]
This simplifies to:
\[ 8x - 4 = 20 \]
Now, add \( 4 \) to both sides:
\[ 8x = 20 + 4 \]
\[ 8x = 24 \]
Now, divide both sides by \( 8 \):
\[ x = \frac{24}{8} \]
\[ x = 3 \]
Thus, the solution to the equation is:
\[ \boxed{3} \]