First you should take this slope equation and rearrange it into point-slope form. Point slope form of a line is y=mx+b, with m being the slope and b representing the y-intercept.
-4x-2y=4
-2x-y=4
-y=2x+4
y=-2x-4
Now that we have the equation in point slope form, we can look at it and figure out what the slope is based on knowing y=mx+b.