Answer
$f(x)=3x-6$
Work Step by Step
We are given the points $(2,0)$ and $(4,6)$. We can use the slope formula to find the slope of a line going through these points.
$m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}=\frac{6-0}{4-2}=\frac{6}{2}=3$
Next, we can use this slope and one of the given points to write the line in the point slope form $y-y_{1}=m(x-x_{1})$.
$y=f(x)=3(x-2)=3x-6$
