The given functions are
[tex]\begin{gathered} g(x)=4x-5 \\ f(x)=3x+2 \end{gathered}[/tex]The expression (g-f)(-9) means we have to subtract these functions, then we have to evaluate them for x = -9.
[tex](g-f)(x)=g(x)-f(x)=4x-5-(3x+2)[/tex]Now, we simplify this expression
[tex](g-f)(x)=4x-5-3x-2=x-7[/tex]Now, we evaluate for x = -9.
[tex](g-f)(-9)=-9-7=-16[/tex]