or you can do the easy way
convert to slope intercept
y=mx+b
m=slope
get 1y all by itself
8x-4y=8
minus 8x both sides
-4y=-8x+8
divide both sides by -4
y=2x-2
y=mx+b
slope is 2
the hack way is
for an equatoin in standard form
ax+by=c
slope=-a/b
slope=2
if you want to graph 2 points and do it the long way, here it is
if x=0, y=-2
if y=0, x=1
(0,-2) and (1,0)
slope=(y2-y1)/(x2-x1)
slope=(0-(-2))/(1-0)=2/1=2
slope is 2