Use intercepts to graph the line described by the equations-2x-4y=8

-- The x-intercept is the point where the line crosses the x-axis.
So y=0 there.

           -2x - 4y = 8
          -2x - 4(0) = 8
          -2x          =  8

Divide each side by  -2 :   x = -4     =>  the x-intercept is  (-4, 0)  

-- The y-intercept is the point where the line crosses the y-axis.
So x=0 there.

           -2x - 4y = 8
         -2(0) - 4y = 8
                  -4y = 8

Divide each side by  -4 :   y = -2     =>  the y-intercept is  (0, -2)    

Now you have two points on the graph ... the points where the line crosses each axis.

Mark little dots at both points, then lay your ruler across both dots, and draw
the line along the edge of the ruler, as far as you want to in both directions.