Answer:
-1
Explanation:
Find components of the definition.
[tex]f(x+h)=-h-x+1\\f(x)=-x+1[/tex]
Plug in components
[tex]\frac{f(x+h)-f(x)}{h} = \frac{-h-x+1-(-x+1)}{h}[/tex]
Simplify.
