We need to find the value of the following expression:
[tex](12-x)+\frac{y}{2}[/tex]When x=4 and y=-8. This basically means that we must replace x with 4 and y with -8:
[tex]\begin{gathered} (12-x)+\frac{y}{2} \\ (12-4)+\frac{-8}{2}=8-4=4 \end{gathered}[/tex]Then the value of the expression when x=4 and y=-8 is 4.