Answer
$(0,3)$ and $(1,-1)$ are located on the line.
$(4,0)$ is not located on the line.
Work Step by Step
$\textbf{To determine whether a point is on a line, simply plug the points back into the equation}$.
When we plug in $(0,3)$ and $(1,-1)$ into the equation of $y=3-4x$ as $x$ and $y$ respectively, the equation works out, which indicates that the points are located on the line.
But when we plug in $(4,0)$ into the equation, the equation is not work out, which indicates that the point is not located on the line.