Question 123007
SLOPE=(Y2-Y1)/(X2-X1)=(0+2)/(0-2)=2/-2=-1
{{{ graph( 200, 200, -5, 5, -5, 5, y = -x) }}} (graph 200x200 pixels, x from -5 to 5, y from -5 to 5, y = -x).