Answer
$\color{blue}{\bf{(a) 2-x-h }}$
$\color{blue}{\bf{(b) -h }}$
$\color{blue}{\bf{(c) -1 }}$
Work Step by Step
We are given the function: $\bf{f(x)= 2-x }$
$\bf{(a)}$ We are asked to find $f(x+h)$
$2- (x+h) $
$\color{blue}{\bf{ 2-x-h }}$
$\bf{(b)}$ We are asked to find $f(x+h)-f(x)$
$2-x-h-(2-x)$
$2-x-h-2+x$
$\color{blue}{\bf{ -h }}$
$\bf{(c)}$ We are asked to find $\dfrac{f(x+h)-f(x)}{h}$
$\dfrac{ -h }{h}$
$\color{blue}{\bf{ -1 }}$