Answer
$ f(x)=-3x+4$
Work Step by Step
$f(2)=-2$ can be written as $(2,-2)$ and $f(1)=1$ as $(1,1)$
Slope $m=\frac{1-(-2)}{1-2}=\frac{3}{-1}=-3$
Point-slope form is
$y-y_{1}=m(x-x_{1})$
Using the values of slope $m$ and point $(1,1)$, we get
$y-1=-3(x-1)$
$\implies y-1=-3x+3$
$\implies y=-3x+3+1$
$\implies y=-3x+4$
A function is
$ f(x)=-3x+4$
