$\displaystyle 8x+y=5\Rightarrow y=-8x+5\Rightarrow m=-8$ (m is the slope)
The equation is $\displaystyle y-y_0=m(x-x_0)$, where $\displaystyle (x_0,y_0)=(0,1)$
Once the substitutions are made in the above point-slope form of the linear equation, it must then be transformed into the requested slope-intercept form.