Answer
$f(x)=\frac{1}{2}x$.
Work Step by Step
We write $f(-4)=-2$ as $(-4,-2)$ and $f(-2)=-1$ as $(-2,-1)$.
Slope of the line that passes through $(-4,-2)$ and $(-2,-1)$ is
$m=\frac{-1-(-2)}{-2-(-4)}=\frac{1}{2}$
The line crosses the y-axis at the point $(0,0)$. So, the y-intercept is $b=0$.
The slope-intercept form is
$y=mx+b$
$\implies y=\frac{1}{2}x+0$
$\implies y=\frac{1}{2}x$
A linear function is $f(x)=\frac{1}{2}x$.
