Answer
$$2$$
Work Step by Step
The slope $m$ of a line is given by
$$m=\frac{y_2-y_1}{x_2-x_1}$$
where $(x_1,y_1)$ and $(x_2,y_2)$ are two different points on the line and $x_1\neq x_2$.
For a line through the points $(4,-1)$ and $(3,-3)$
$$m=\frac{-3-(-1)}{3-4}=\frac{-2}{-1}=2$$
