Simple...
you have: 8x-6y=1
To find m (slope) re-write in y=mx+b form
8x-6y=1
8x-6y=1
-8x -8x
-6y=-8x+1
Now simply divide by -6--->>
[tex] \frac{-6y}{-6} = \frac{-8x+1}{-6} [/tex]
[tex]y= \frac{4}{3} x- \frac{1}{6} [/tex]
m=[tex] \frac{4}{3}x [/tex]
Thus, your answer.