Since the graph is a linear function, we're going to use the slope formula solve this:
Note I am replacing m with k
[tex]k= \frac{ y_{2}- y_{1} }{ x_{2}- x_{1} } [/tex]
Inserting 2 points from the graph, let's use (1,8) and (2,16).
[tex] \frac{16-8}{2-1}
[/tex]
k=8