First step, find the slope of the line, which is the change in y/change in x
m= -4-0/4-0 = -4/4 = -1 m=-1
Now you can use one of the coordinates and the slope to set up a linear equation in point-slope form
y-(-4)= -1(x-4)
Distribute
y+4= -1x+4
Get y by itself by subtracting 4 from each side
y= -1x+0
Now the equation is in slope-intercept form, just one more step to get it into standard form. Move the x value to the side with y by adding 1x to each side.
x+y=0
