Question

if someone could explain what i plug into f??

Answer 1

You are correct with part i with what you did so far, but you need to finish it.
What is function f?

i.
$\dfrac{f(9) - f(2)}{9 - 2}$

ii.
$\dfrac{f(1) - f(0)}{1 - 0}$

iii.
$\dfrac{f(9) - f(-7)}{9 - (-7)}$