To graph equations like y = -x -12
Since this is in slope intercept form we are automatically given the y-intercept which in this case is -12 so (0,-12)
the coefficient in front of the x is the slope, in this case it is -x so that means -1/1 or -1
To graph this you would plot a point at the y-intercept, then down one over one (negative slope means down instead of up) then to the right, however long to create a line
Hope this helps :)