how do I graph slope -2/3 passing through point (2,1)
Plot the point (2,1)
Plot the point 3 left and 2 up from it, i.e. (-1,3)
Draw a line through those two points.
The point 3 right and 2 down works as well, i.e (5,-1)
More generally, if you want the equation of the line in the form y = mx + c, then m = -2/3 and you find c from: 1 = -(2/3)*2 + c (so c = 7/3).