Use the two points to find the slope. X changes by 4 while y changes by -2 so the slope is -.5. Then put it in point slope form. We'll use the point 1,0. So y-0=-0.5(x-1). Simplify it down to y=-0.5x+0.5 then carry over the x to the other side to 0.5x+y=0.5. That's how I did it, but there's probably a more efficient way to do it.
