First, you must find the slope, which is -5-4/-1-4, or 1.8, and then put it in point-slope form, or y-4=1.8(x-2), which simplifies to y-4=1.8x-3.6, and so put it in general/standard form, you have to subtract 1.8x from both sides and then add 4 to both sides, and lastly divide both sides of the equation by -1.8 to get x+y=1.889, or x+y=1.6/1.8. This is not copied and pasted.