I can't see pictures, but to graph y=-4x, you have to make -4x into slope form.
Just write -4 as a fraction, or -4/1. -4 is the rise, and 1 is the run. So start at the origin, or (0,0), and go down 4 units, then 1 unit right. So you start at (0,0), then now you should be at (1,-4). Repeat the process to make a straight line.
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hope it helps