To determine the value of \( y \) that satisfies the equation \( y = \frac{1}{2}x - 2 \) when \( x = 4 \), we should substitute \( x = 4 \) into the equation and solve for \( y \).
Step-by-step, the process is as follows:
1. Start with the given equation:
[tex]\[
y = \frac{1}{2}x - 2
\][/tex]
2. Substitute \( x = 4 \) into the equation:
[tex]\[
y = \frac{1}{2}(4) - 2
\][/tex]
3. Calculate \( \frac{1}{2}(4) \):
[tex]\[
\frac{1}{2} \times 4 = 2
\][/tex]
4. Subtract 2 from the result:
[tex]\[
2 - 2 = 0
\][/tex]
Therefore, the value of \( y \) when \( x = 4 \) is \( 0 \).
Thus, the correct answer is:
B) 0
