1/2•(16-y)=4

To solve the equation \( \frac{1}{2}(16 - y) = 4 \), follow these steps:

1. Eliminate the fraction by multiplying both sides of the equation by 2:

   \[ 2 \cdot \left( \frac{1}{2}(16 - y) \right) = 2 \cdot 4 \]

   This simplifies to:

   \[ 16 - y = 8 \]

2. Isolate \( y \) by subtracting 16 from both sides:

   \[ -y = 8 - 16 \]

   This simplifies to:

   \[ -y = -8 \]

3. Multiply by -1 to solve for \( y \):

   \[ y = 8 \]

Therefore, the solution is \( y = 8 \).