Solution:
Given:
[tex]f(x)=4x-8[/tex]To reflect a function f(x) across the y-axis, the rule below applies;
[tex]f(x)\Rightarrow f(-x)[/tex]Hence, the new function g(x) is;
[tex]\begin{gathered} g(x)=f(-x) \\ \\ Hence, \\ g(x)=4(-x)-8 \\ g(x)=-4x-8 \end{gathered}[/tex]The graph of both functions is shown below indicating the reflection across the y-axis.
Therefore, the equation of the resulting function is;
[tex]g(x)=-4x-8[/tex]