[tex]\bf \begin{array}{lllll}
&x_1&y_1&x_2&y_2\\
% (a,b)
&({{ 0}}\quad ,&{{ 0}})\quad
% (c,d)
&({{ 3}}\quad ,&{{ 4}})\\
&origin
\end{array}
\\\\\\
% slope = m
slope = {{ m}}= \cfrac{rise}{run} \implies
\cfrac{{{ y_2}}-{{ y_1}}}{{{ x_2}}-{{ x_1}}}\implies \cfrac{4-0}{3-0}\implies \cfrac{4}{3}[/tex]
so, that's the slope of a line passing through the origin and 3,4, and any line parallel to it, will have the same exact slope.
