Explain Graphing Equations with a Negative Slope?

If the slope is a negative fraction, place the negative sign on either the numerator or the denominator.
Example graph y = -2/3 x-1
The slope is -2/3. There are two ways to assign the negative:
Case 1: The numerator is -2 and the denominator is 3.
Case 2: The numerator is 2 and the denominator is -3.
In Case 1, since the numerator is -2, you move down 2 units; the denominator is 3, so move to the right 3 units.

In Case 2, since the numerator is 2, you move up 2 units; the denominator is -3, so move to the left 3 units.