according to the graph what is the value of the constant in the equation below

well, let's take a look at the graph hmmmm as "x" is moving further towards the right, the line is going down, or namely "y" is lessening and lessening, which is another way to say that "y" is inversely proportional to "x".well, we know a few points on the line hmmm let's use say hmm (10 , 8) to get the constant of proportionality.  Any point will do btw, we're just using this one.[tex]\qquad \qquad \textit{inverse proportional variation} \\\\ \textit{\underline{y} varies inversely with \underline{x}} ~\hspace{6em} \stackrel{\textit{constant of variation}}{y=\cfrac{\stackrel{\downarrow }{k}}{x}~\hfill } \\\\ \textit{\underline{x} varies inversely with }\underline{z^5} ~\hspace{5.5em} \stackrel{\textit{constant of variation}}{x=\cfrac{\stackrel{\downarrow }{k}}{z^5}~\hfill } \\\\[-0.35em] \rule{34em}{0.25pt}[/tex][tex]\stackrel{\textit{"H" varies inversely with "w"}}{H=\cfrac{k}{w}}\qquad \textit{we know that} \begin{cases} H=8\\ w=10 \end{cases} \\\\\\ 8=\cfrac{k}{10}\implies \boxed{80=k}[/tex]