Answer
$y=2x$
Work Step by Step
The equation for a line defined by a point and slope is $y-y_{1}=m(x-x_{1})$ in which $m$ is the slope, which we can calculate from $m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$, where $x_{1}$, $x_{2}$, $y_{1}$ and $y_{2}$ are the coordinates of given points, so therefore...
$m=\frac{2-8}{1-4}=\frac{-6}{-3}=2$
$y-2=2(x-1)$
$y=2x-2+2$
$y=2x$
