To find the value of \( y \) when \( x = 9 \) in the equation \( 8x - 2y = 48 \), we start by substituting \( x \) with \( 9 \):
\[ 8(9) - 2y = 48 \]
Now, calculate \( 8(9) \):
\[ 72 - 2y = 48 \]
Next, we isolate \( -2y \) by subtracting \( 72 \) from both sides:
\[ -2y = 48 - 72 \] \[ -2y = -24 \]
Now, divide both sides by \( -2 \):
\[ y = \frac{-24}{-2} \] \[ y = 12 \]
The value of \( y \) is \( 12 \).