y-9=1/7x(x-8)

I assume you possibly want to graph

y - 9 = (1/7)(x - 8)  =

y = (1/7)(x-8) + 9

Here it is..........https://www.desmos.com/calculator/qeyrsikjbz

(You may have to scroll up on the Desmos page to see the graph....)