To evaluate [tex]8x[/tex] at [tex]x=0.5[/tex], we just have to plug in [tex]0.5[/tex] wherever we see [tex]x[/tex].
After substituting [tex]x=0.5[/tex] for every value of [tex]x[/tex], we then simplify.
So, on substitution, we have
[tex]8x=8(0.5)[/tex]
Change the [tex]0.5[/tex] to [tex]\frac{1}{2}[/tex] to help you multiply easily.
[tex]\Rightarrow 8x=8\times \frac{1}{2}[/tex]
Simplify to obtain,
[tex]8x=4[/tex]
