Answer
$ f(x)=x+2$
Work Step by Step
$f(5)=7$ can be written as $(5,7)$ and $f(-2)=0$ as $(-2,0)$
Slope $m=\frac{0-7}{-2-5}=\frac{-7}{-7}=1$
Point-slope form is
$y-y_{1}=m(x-x_{1})$
Using the values of slope $m$ and point $(-2,0)$, we get
$y-0=1(x-(-2))$
$\implies y=x+2$
A linear function is
$ f(x)=x+2$