Answer
Slope of the line $ y = mx$ is $m$.
Work Step by Step
It is given that this line passes through the origin, $(0,0)$ and point $(1,m)$. Substituting into our formula $ m =\frac{(y_2 - y_1)}{(x_2 - x_1)}$ we get $ m =\frac{(m - 0)}{(1 - 0)}$, which leaves us with $m = m$.