I think that one of your x terms needs to be y.
lets assume your equation was -4y-16x = -12
we know that the slope intercept formula is y = mx + b
so we need to get your equation into the same format
-4y -16x + 16x = -12 + 16x
-4y = 16x -12
divide each side by -4
-4y/(-4) = (16x - 12)/(-4)
which gives you (the slope intercept equation for the line)
y = -4x + 3
using this line and slope intercept formula you know that the slope, m =-4 and your y-intercept , b = 3
your y-intercept is the value of y on your line when x = 0 so you have one point (0,3)
You need another point to draw/graph the line
Now another way of looking at your slope is knowing that it is equal to the change of y divided by the change in x
m = (y_{1}-y_{2})/(x_{1}-x_{2})
since your slope is -4 which can be written as -4 = -4/1 using the concept above you could take your point (0,3) and know that if you moved y 4 points down on the graph and x one point to the right you would get the next point (1,-1). You can then graph your line using those two points
OR you could substitute in different values for x into the slope intercept equation for the line and determine a new y
y = -4x + 3
using x = 1, y = -4(1) + 3 = -4 + 3 = -1 point (1,-1)
Which is the same as the value of the point you would get from moving along the graph. I hope this helps