a simple way to get the coordinates of the vertex, is, the constant outside the bars is the y-coordinate of the vertex, and to get the x-coordinate, we can simply find what values of x makes the barred expression to 0, and we can do that by simply zeroing out the barred expression and solving for x.
![\bf f(x)=|3x-4|\implies f(x)=|3x-4|+\stackrel{\stackrel{y-coordinate}{\downarrow }}{0} \\\\\\ \stackrel{\textit{to get the x-coordinate}}{3x-4=0}\implies 3x=4\implies x=\cfrac{4}{3} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill \stackrel{vertex}{\left( (4)/(3),0 \right)}~\hfill](https://img.qammunity.org/2019/formulas/mathematics/high-school/k22ekuczs09fb9n5hp0woy6feb0zyk3g5z.png)