Substitute the point (4,-3) into the equation 1-kx = -3y

(Note: Why can we do this? Because when a point lies on a line, if you sub the x coordinate into all 'x's in the equation and y coordinate into all 'y's in the equation, then you will get left hand side equals right hand side.)

1 - 4k = -3(-3)

1 - 4k = 9

4k = 1 - 9 = -8

**k = -8/4 = -2**