You can put this solution on YOUR website! THERE IS NO SLOPE DEFINED FOR A SINGLE POINT.
IF YOU MEAN (2,0) & (0,3) THEN:
SLOPE=(3-0)/(0-2)=3/-2=-1.5 FOR THIS SLOPE.
Y=mX+b
0=-1.5*2+b
b=3
Y=-1.5X+3 is the line equation through (2,0) & (0,3). (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, -1.5x +3).